Remove parts, T moulding, coin door ECT....Soak a rag in automotive grade reducer (not acetone), And get a spot about a foot square wet, really drippy wet with a gentle "polish on" motion, and wipe it off almost immediately with a dry rag in the other had "polish off" motion...And work your way around the whole panel like that not letting it saturate, (Or it will lift the paint underneath) for awhile it will seem nothing is happening but after about the 4th pass it should start to give. don't get excited and start scrubbing it or it will lift the paint... Just keep after the white stubborn spots like above, (polish on, polish of) Eventually it will be gone with a white haze over the original paint, let dry (at least overnight) and do it again with clean rags, It takes about 2 gals of reducer, and ten pounds (give or take) of clean cotton rags, Use adequate ventilation, cause it will be a toxic stinky vapor mess....Its not usually worth the trouble however, the paint underneath most likely has issues, (why it was repainted) If so sand it smooth repaint and cover with vinyl pac art, or repaint and stencil.