It really is easy and difficult to mess anything up. Even if you somehow mess up the power supply, you can buy a new one but never heard of anyone having to do that. Technically there really is not much of a warranty to begin with so this makes no difference. Plus, pretty much everyone is installing mods of some sort so it's hardly abnormal.

The power supply is super easy to access inside the backbox and easy to open up with simple tools. You need an exacto knife or something sharp to cut away at the spray silicon stuff holding the fan wires down. Nothing complicated. Then you just unplug the stock fan and plug new one in. Just pay attention putting things back together. I didn't and ended up pinching some wires bolting everything back in place. Game had some distortion/noises in speakers but once I freed the wires everything was fine.