Last year I rebuild my CB 450. I spent days trying to get the old gaskets off. I finally used a putty knife that I honed the end to a nice sharp endge. Razor blades will dig into the aluminum. I came across a product in the cabinet called Goo Gone. I assume it is available in the grocery store. I was scrapping off the clutch cover gasket and having my usual amount of difficulty. I put some of this stuff on and let it sit for 20 minutes. The removal effort was reduced by 50%.
Your wife may have some also. Give it a try. Helps out a nasty job.