You don't need to know the exact glue. 99% iso has worked great for me. You can find out pretty quickly if a solvent will work or not. I really, really prefer gently lifting the stuff off than chiseling away with an exacto or tugging it off. I'm sure there's not one single correct method - if you can get it off without destroying it, you're good.
As for getting it back on - I've read about using hand sanitizer, which is sort of gelatinized alcohol. Allows you some leeway to slide the stuff around before it evaporates. Need to try that some time, don't know if that would work with pliobond, but for replacing with a new leatherette that's self-adhesive, I imagine it would..