Hi 👋 my cat has a long woolly coat which matts a lot as she is getting old and has arthritis so is unable to groom herself.
She is a diva and will bite and attack if she feels like it usually in the middle of brushing her, brushing is only allowed if she sits on my knee or if she is lying outside in the sun.
Otherwise she runs away and would be really stressed if we chased her.
She is an angel at the vets 
so they usually remove any matts with a shaver while I do my best at home.
I bought a pet clipper to hopefully help get rid of the matts but was really worried about causing her stress. I watched some YouTube videos of shaving a cat, they were horrible all the cats were clearly unhappy 
Clippers came Thursday, I put the no 12 guard on and used it switched off as well as her brush, she was quite intrigued by it, I put it on my arm and switched it on, she sniffed it but didn't move so I put it gently on her and slowly brushed, she was ok with it. Yesterday she was lying in the sun and I was able to shave a bit more and last night got lots of hair. She still has her matts but is is only day two and as much as I wanted to get it all done, a bit at time if that's what she wants, I think she likes the vibration maybe it's like a massage 
I will probably leave the 12 guard on until I have managed to finish her, then check and reassess
Sorry for the long post, but I hope it helps if anyone is thinking of doing the same