Take everything very slowly, and use lots and lots of positive reinforcement in the form of VERY yummy treats to convince her that grooming is good. It sounds like she hasn't been groomed a lot, so it may not be that she doesn't like grooming, but that she's afraid of it.
Turn the clippers on and let them run (sit them on the table or floor beside her) while feeding her super yummy treats. Then turn it off and stop feeding. Repeat the cycle several times over a few days, and eventually when you turn the clippers on she'll get excited and start looking for treats.
Next step is to have the clippers beside her face, ears, body, etc while somebody else continues feeding her the awesome treats as long as the clippers are running. Always stop the flow of treats once the clippers are off. You want Bella to realize that the clippers mean treats, and that it's a VERY good thing when the clippers come on.
Next step is to actually start using the clippers while a helper (husband? friend?) feeds her. At this point peanut butter might be easiest to use, since she can lick it off a spoon or fingers. By this point, Bella should be much more relaxed about grooming, and you shouldn't have to worry about biting.
HOWEVER, if she continues to attempt to bite (or snap) then I recommend using a nylon muzzle to protect yourself while grooming. Her bites would most likely be fear-related, so it wouldn't be her deliberately trying to hurt you.
Hope this helps!