Even though it requires the most elbow grease, the safest way is to sand as much of it off as possible. Once you start trying to chemically strip it, you run a lot larger chance of ruining the paint underneath. The stripper won’t care what layer of paint it is, it will attack either equally. Once you get the majority of it off sanding, I would use good ol’ acetone to do some finer clean up. The orginal paint is going to be faded/scuffed, so just wet sand it with a higher grit sand paper, and then use some rubbing compound to bring the shine back. Sounds tedious, but it will give the best results. The strippers will also work, but there is the potential for catastophe. Like any time you sand/buff paint, be careful not to burn through all the layers.