How to Disassemble a Computer Step 1: Unplugging. The first THING you do, is unplug every cable that's plugged in to your computer. ... Step 2: OUTER Shell/Casing. ... Step 3: Outer Shell/Casing (cont.) ... Step 4: System Fan. ... Step 5: CPU Fan. ... Step 6: Power SUPPLY. ... Step 7: CD/DVD Drive[s] ... Step 8: CARD Reader.