I bought a 2011 Macbook Pro, and after unscrewing the cover to install RAM and an SSD, the laptop wobbles while I'm typing. This is really annoying; is there a fix that doesn't involve shipping my laptop away for days or having it replaced with a new one?
It sounds like you over-tightened a screw, or tightened them unevenly - ie, tightened one all the way before tightening the others.
Try loosening them a bit and seeing if the wobble disappears. If it does, just make sure to tighten them evenly without over doing it.