I would second the diesel. Let it soak in diesel or a penetrating oil if you have enough of it. I've run into your kind of predicament before and chances of keeping the paint in good shape aren't great. Letting it soak might keep ya from destroying the paint but with what you're describing I wouldn't be too hopeful. Sorry probably not what you want to hear.
Sent from my SM-N970U using Tapatalk
Sent from my SM-N970U using Tapatalk