One problem with these old beasts is the bottom rubber can detach. Apple used to provide free replacements, but that program ended more than a year ago.
So what do you do to fix the bottom? It's easy! Here's what I did:
- Remove the bottom plate by removing the 8 bottom screws.
- Fully peel off the failed rubber and fully expose the aluminum.
- Use small pieces of permanent tape on the "back side" of the lid to cover the drill holes in the aluminum.
- Fully clean the "exposed side" of the aluminum plate.
- Apply small stick-on rubber feet to each corner.
- Coat the "exposed side" of the plate with several coats of Plasti-Dip spray paint. I picked red, but there are many colors available.
- Re-attach the bottom plate to the laptop.