Aircraft remover is what body shops use to remove paint without sanding. Not "paint thinner". Lacquer thinner will not remove paint without damaging the plastic. You don't want any of these things around your car unless you are trying to wreck the finish. If you get a body shop to paint them, you should tell them to remove the handles. If you paint them on the car, you risk overspray elsewhere, and it is near impossible to paint the inside part of the handle if it is still connected to the door.
Just my two cents, after working in body shops for 10 years.