Things You'll Need
Instructions
Shut-down your computer, and unplug all the electric power sources. Remove the side access panel by unscrewing it from the computer tower.
Attach the anti-static wristband to your computer with an alligator clip. Wrap the other end of the wristband around your hand.
Unscrew the four screws attached to the power supply, and take it out of its case.
Check the power supply requirements of your video card, if you are upgrading wattage for gaming. Otherwise, check the wattage of your current power supply source. Based on this information, purchase a power supply that is higher wattage than the minimum requirements of your video card or of your current source.
Insert the new power supply into the case. Replace the screws on the panel of your computer. Reattach the power cords, and plug them in to establish your new upgraded wattage.