You'll have to pull the disposal and reseal it with plumbing putty.
DONT' try to PRY anything.... it's all held together by locking rings
that are easily removed - if you know how to.
It's really not all that difficult, search this group for 'disposal'.
Instructions are here in lots of places on how to remove and replace a
disposal. Or use google, or, since you are going to have to have some
plumbers putty anyway, or pick up a plumbing "how to" book when you go
buy the putty.