It's not as difficult as you might think, as James Hunt explains
Although it's common to want a more efficient cooler for your CPU or better extractor fans for your case, most people would never dream of taking their graphics card to bits to improve the cooling. Yet it's entirely possible to do just that.
In a way, it's understandable. Graphics cards are expensive and don't seem to be user-serviceable: unlike processors, the cooling systems come pre-attached. But like CPUs, if you improve the cooling on your graphics card, you might find that you get better performance out of the hardware. Overclocking a GPU is easier than overclocking a CPU, such that you can do it in software, and if anything goes wrong, it's easier to recover from as well. The performance hike you get will also be far more relevant to gaming than an overclocked CPU would be.
That said, replacing GPU fans isn't just about performance. Learning to replace your fan might be the difference between a card you have to junk and a card you can hang on to or resell. It can reduce the amount of noise you get out of your system. It might even allow you to save power. All you have to do is take the plunge and remember that there's no real difference between a GPU and a CPU except the name. If you can change a fan on your main processor, there's no reason you can't do it on your graphics card.
The Tools
In fairness, while the principles of replacing a cooler on your graphics card are the same as replacing one on your CPU, things aren't quite so straightforward. It's not quite as simple as popping out some plastic bolts and pressing down hard. You will need the following:
Your Replacement Cooler
Be it a fan, heatsink or liquid-cooling hybrid, you'll need to start this process by picking a replacement cooler. Prices range from a couple of quid for a replacement fan to well over a hundred for the super-efficient multi-fan. You'll have to check whether they fit your card, but broadly speaking, third-party coolers are built to be compatible with most designs.
A Couple Of Phillips-Head Screwdrivers
You need one for removing the graphics card from its slot and another, much smaller one for removing the existing housing and coolers on your graphics card.
Thermal Paste
This will probably come with the cooler either as a preapplied square or as a packed-in tube, but if it doesn't you'll need to get some. As with CPUs, thermal paste allows you to connect heatsinks and fans to the GPU in a way that allows heat to be quickly conducted into the cooling elements of the device. Without it you might as well be flapping a newspaper at the processor. If you leave out or misapply the thermal paste, you can expect to burn out your hardware fairly quickly, so make sure this doesn't happen!
A Dry Tissue Or Anti-Static Cloth
As ever, you should also take care not to cause a static shock in any of the components while handling them. This can be avoided fairly easily by touching a radiator to ground yourself beforehand, but it's also worth taking care not to scuff up against carpet or rub balloons on yourself during the process.
If you need to wipe your card or its components (whether to clean dust or remove errant thermal paste), then you should always use a dry cloth or piece of tissue. Try to dab rather than wipe to avoid spreading the dirt or snagging fragile components. If you use a cloth, make sure it's anti-static so you don't accidentally fry your hardware!
The Process
Before you begin doing anything with the hardware, it's worth running a benchmark on your card. This will give you the base levels of performance and temperature so you can compare the results later. The best way to know you've done something right is that these numbers improve, and the best way to discover you've done something wrong is if they don't. You can use a program such as GPU Shark to get some quick baseline values, and only then should you shut down your PC so you can start the cooler replacement process.
Begin by removing the card from its PCI slot, taking care to disconnect any power cables or extensions that may be present, such as an SLI bridge or LED power cords. Place it on an anti-static surface (i.e. not your carpet).
Use the screwdriver to remove the existing case (if applicable) and cooling unit. You may want to take reference photos so it's easier to reassemble. Picking the right screws to remove at the right time can be difficult, but it makes most sense to start with the ones on the side of the card since they usually hold the cooler on. If those don't look right, look under the fan blades, because screws there are sometimes used to fix the fan housing onto a heatsink.
You may also find an assembly bracket on the bottom of the card, which you'll have to remove before you can remove the fan. Each card is different, so if you want to be certain what you're doing it might be worth looking up your particular model on YouTube to see if there are any instructional videos available.
Once the cooler is loose, find and remove the fan's power cable. This is normally a standard three-pin connector with red, black and yellow wires - only instead of attaching to the motherboard, it's attached to the graphics card. Remember that if the card has multiple fans, you'll probably have multiple fan power sockets.
If the heatsink is separate, it may require a little twist or pull to disconnect it from the GPU itself. Don't force it, though; thermal paste isn't glue, so if the heatsink won't move, it's probably connected to the card in a way you've missed. Once the GPU has been exposed, wipe the paste away with dry tissue or an anti-static cloth. Do not press down too hard or you risk damaging the GPU!
Now, unpack your new cooler and reapply an appropriate amount of fresh thermal paste to the GPU. It doesn't need to be much - only enough to mostly cover the chip once it's pressed flat. Somewhere between a grain of rice and a small pea-sized blob is more than enough. Once that's in place, you can put the new cooler on top and screw it into place starting with two opposite diagonals to keep the pressure even. Again, don't screw too hard otherwise you risk damaging the chip.
Some guides will recommend that you spread the paste over the whole chip first, but we prefer to let the cooler squeeze it into place, which helps avoid air bubbles. Try not to slide the cooler around once it's attached - you want to paste to stay in contact with the CPU and cooler and nothing else, otherwise heat will spread in the wrong direction and into the wrong components. When the cooler has been screwed into place, you can then reconnect the power cable and replace the case.
At this point, it's advisable to test your card, even if everything seems to have gone well. Place it back in your PC and use your GPU monitoring program to test its performance. If you got everything correct, the temperature should be lower than before - or at the very least the same. If the temperature has gone significantly up, you may have used too little thermal paste or otherwise misapplied the cooler, so investigate any errors carefully. The most common problems are that the thermal paste has been applied wrong or the fan's power cable was attached incorrectly and isn't working. Whatever the reason, if your card's temperature shoots up, then shut down immediately and investigate!
If your temperature has gone down, then good news; your card will be less stressed, and you now have some overhead for overclocking, if that was your goal. Either way, be proud that you've successfully replaced your GPU cooler. Wasn't so hard after all, was it?