As has been mentioned if it is still that stable a surface they can just paint over it. If they still insist on removing it, if it is an oil based paint sodium hydroxide will break it down and make it easier to remove but keep it off you because it burns. Sodium Hydroxide will “help” with it is water based if it has badly failed but it does not have the same effect on water based that it has on oil and it has next to no effect on water based that is in good shape. If you don’t know what type of paint it is, use some denatured alcohol on a rag and rub vigorously. If it comes off, it is water based, it won’t do anything to oil based. Good tip for fences and decks too.