If they're Altec woofers with doped surrounds that have been in place for a long time, the surround dope has probably migrated and re-set effectively gluing the gasket and part of the surround to the baffle. I wouldn't try to shove anything between the baffle and gasket without first softening with heat, a blow dryer on a medium setting works great for this. Usually a good even application of heat alone is enough, and no prying or tools are necessary.