Mate I'm probably not the best person to ask, hopefully someone with more experience in paint and bodywork will see this.
Depending how bad it is, I just sand it and repaint (if it even needs it) but if it's really bad I use these type of disk stripper thingies;
These rip paint off anything.
I used to use a normal sanding disk, but only when it was nearly completely buggered so it wouldn't remove anything more than the paint.
To be honest I don't waste too much effort to get them pretty, I make them work as best as I possibly can, if it has to be pristine so you could eat your dinner off it I'm not the guy to bring it to lol
So as I said hopefully someone else who knows better will see this and educate us both!