I would first cut the covering away from some of the open bays between ribs & stringers to first determine how large an area that needs to be removed for repairs. On the sheeted areas, first try peeling a small amount of fabric off of the wood. If it doesn't peel easily, then plan B would be to aggressively sand the finish off of the area to be removed. Sand down until the fabric is fuzzy, but not through it. Then, with good ventilation, brush some lacquer thinner on to soften the dope. After a few moments, the fabric should peel right off.

Then, with such a classic aircraft, PLEASE refinish it in fabric again!

Gary