A frozen winch needs to be
taken apart, cleaned, and any broken parts replaced. I suggest getting a manual or diagram of your winch, either on line or from the manufacturer. When you get ready to take it apart, take some digital images of each stage so you'll have a record and be able to reverse the process. Not sure if this helps, but the only winch I ever had that froze was a small 2-speed Barient. After prying off the top clip, I could not raise the drum off the spindle no matter what I tried. Finally, in desperation, I put a narrow piece of plywood under the under side of the winch drum, and used a crow bar, moving it around to differenct places under the drum skirt, and prying up. The plywood kept the crow bar from damaging the gelcoat. By prying all around the bottom , the drum finally came off. It seems one of the tiny springs that hold the pawls in place had disintegrated and parts of it worked its way into the gear race -- and causing a lot of friction so that the drum couldn't move. This is sort of like dying from a splinter. I cleaned every thing up with mineral spirits and an old tooth brush, brushed on some white lithium grease on the race, spindle, and inside the drum, replaced the pawl spring and used some 3-in-1 oil on all the pawls, and put it back together. Worked fine every since.