How to remove corroded batteries

I let my camera sit way too long and the batteries corroded. I managed to get the compartment open and two of the batteries out, but the other two (the ones that have the negative end facing out) are stuck in place. Two-part question: 1) How do I get the batteries out, and 2) Once I do (if I do) how do I clean the area to make the camera come back to life? Thanks!