A few warnings and reminders before you start disassembling your computer tower to keep both your unit and yourself safe
1. Fully shut down and unplug the computer before you make any attempts to disassemble the tower.
2. Take off any metal objects on your arms or fingers such as bracelets, rings or watches. Even if your unit is unplugged, there may still be some remaining electric charge.
3. Make sure your hands are completely dry to avoid damaging any mechanical parts as well as to avoid electrocution.
4. Work in a cool area to avoid perspiration for the same reason as seen in the previous number.
5. Before touching any part within the tower, put your hands against another metal surface (such as the computer casing) to remove static charge, which may damage sensitive devices.
6. Prepare a place to keep any screws you may remove. A container or piece of paper with labels for each part (casing, motherboard, CD drive, etc) is ideal to avoid confusion between the similar-looking screws.
7. Handle all parts with care. Place each piece you remove carefully down onto a stable surface.
8. If a component does not come out easily, do not forcefully remove it. Instead, check that you are removing it correctly and that no wires or other parts are in the way.
9. Be careful when holding the motherboard, it’s underside actually quite pointy and able to hurt you.
10. Never attempt to remove the power source, a box attached to the side or bottom of the unit to which all cables are connected.
11. When removing any cables, wires or ribbons, make sure to grasp the wire at the base or head to keep it from breaking.
12. Be careful not to drop any small parts (particularly screws) into unreachable areas such as into the computer fan or disk drive.
13. Take note that the three of the most damaging things to a computer are moisture (sweat, drinking water), shock (electric or from being dropped) and dust (any debris from household dust to bits of food).
Have a safe experience in assembling your computer!