[header] How to replace a power supply [title] Get a large surface to lay our all your parts and a cup to put all the screws that you are going to be taking out in. [title] Unscrew and remove the side panel of your tower and locate the power supply. [title] Before you start messing around inside your pc case, make sure you are grounded so there is no static involved. 
[step] Static can mess up your video card and motherboard. [title] Unscrew the screws (there will be around 4 of them) connecting the power supply to the back of the case and put them in the cup.