From a forum submission:
"I'm trying to remove the trans outer cover on my 71 Roadster but it's stuck on pretty good. Last time I assembled it I used a gasket dressed with Permatex anaerobic sealer. Never had trouble getting things apart with this stuff before, but there is not much to get a purchase on on the cover to get it loose. Before I resort to the ham fisted method of a thin blade between the inner and outer cover to break it loose I figured I would ask if anyone has a better solution"
1. Put the gear lever back on pointing backwards, makes a good hand sized handle to rock the cover back and forth to break the bond with no risk to the surfaces.
My added caviat: You MUST put the pointer retaining bolt and a retaining washer or the inner shaft may not come out, then break if stressed DAMHIK !!!!
2. pix below-actually to just break the gasket/seal