Very carefully.
She's huge, lots of attitude, and no body armor made could be of use.
Thankfully her size works against her and I can keep her still in the sink with one hand against her collarbones.
Because of her size that she works hard to maintain, there are spots she cannot wash.
So I have to be the bad guy at times and toss her fuzzy butt into the sink.
She, of course, doesn't want to 'speak' to me afterwards.
That is EXACTLY what is like with Tank. I lock him in the bathroom with me, and he keeps trying to jump out of the tub. He is so porky though, he doesn't have a scruff I can grab. So, I have to hold his rolls of stomach fat to try to keep him in place. He won't talk to me for a few hours but then forgives me because he needs more food.