Opening up a Wii is not overly complicated if you take your time and keep track of all the parts and screws you remove. The screws are covered by stickers or plastic "feet". You don't really need the stickers, but you probably want to keep the feet and reuse them. Some of the screws are phillips and others are tri-wing. Keep track of which goes where. It's a good idea to keep the screws for each side in a separate ziplock bag.
You can purchase many Wii replacement parts in the Zombie Store.
Stuff you will need:
- A couple of small screwdrivers (phillips, tri-wing)
- Plastic bags to keep track of all the screws
Click on the pictures for a larger version.