I don’t know ‘correct’ way to remove them (bridge thimbles) I have found it’s usually brute force, but if they have an internal thread (which I don’t think yours do) you put a screw in em and pull them out, if they don’t I use a reamer and twist em out, but this usually damages them (but they are cheap), also sometimes heating them helps… just put a soldering iron in the hole for a bit. Another way to go is just leave them in and hand sand right up to them and mask em off when spraying, and on a stang the bridge hardware covers them anyway… also blushing is a problem if lacquer drys too quickly, to eliminate blushing add two or three caps full of lacquer retarder per half pint of reduced acrylic lacquer (about the amount needed for a Fender body) this gives you better control of your solvents, and ultimately, better results… well good luck and post a pic when you are done.