I used a stupid method on an original Godzilla model; it worked and I would NOT recommend it. I sat in a lawn chair with a garden hose and a can of gasoline. I ran the water continuously as I applied gas and the paint came off in a few minutes with scrubbing. Then I wondered if my skin would come off from the red color and pain. After my hands healed, I refinished the model.
After I grew a bit older and hopefully less stupid (I don't believe I'll ever be able to say I am wiser), I reclaimed an Aurora Lockheed XFV-1 by careful sanding and using Microsol on the decals. I polished the canopy with fine sandpaper and finished up with toothpaste on a cloth, and rebuilt the broken tail with thick sheet plastic that I sanded to shape and scribed. Its not a show winner, but its one that I truely love!
Just build a model for the FUN of it!
Gerald