Don't go in there, it is scary! Actually, if you are careful you can use something like acetone to soften up the sealer at the base/edge of the can, and gently pry up with a small flat-blade screwdriver or even a paint-can lid removal tool as you go around. Someone might recommend some other type of solvent, I wouldn't use anything too severe though, and try not to get it on the surrounds foam.
I always recommend sending the cans to John at Ohm, but for those that want to DIY, I say go for it. The Ohm's are fun speakers to have around, hope you can get yours working. I enjoy my MWT's and Walsh 3/3000's. Tim