I have the vet do it.

Karen

Thank you for all the helpful feedback.  I have never used any kind of
trimmer for sideburns or children's hair (the cat IS my child) and
don't own any such thing.  I guess I'll have to see what I can find.
Even though she's a very sweet and generally obliging kitty I suspect
that approaching her back end with anything that ummm...buzzes? might
not go over too well!  This should be an interesting task - guess I
should have stuck to short-haired kitties. I never planned to fall for
this fluffy little girl, it just worked out that way.  Oh well, what
can you do!

Some of the trimmers aren't very loud at all and might not freak out the
cat. If you don't have easy access to a vet or groomer it might be worth
picking up a set. I don't imagine you'd have to trim all that often as it
does take a while for the fur to get long again. If kitty will let you comb
the fur back there it will probably get used to being clipped.

We had a cat years ago who didn't want us messing around anywhere near her
hind quarters. Well she got into a cat fight and ended up with an abscess
back near her tail. We had to take her to the vet to get it treated. When
they sent her home she had two "holes" one by the tail and one near her hip.
We had to flush with peroxide and run a q-tip in one hole, under the skin
and out the other (for as long as this was possible) to ensure it healed
from the inside out. I had visions of flying teeth and claws when the vet
told us what we had to do to her. Surprise surprise, I didn't even have to
wrap her in a towel. She would lay across my lap as still as she could while
I did this to her. Never once did she even turn on me. I guess if it
benefits them they can learn to put up with it.