The vet's girls always try to EXPEDITE things (they do have a waitingroom full of other pets..) by making a 2-person rodeo with our dogs. Force, fighting, struggle, violation is all the dog takes away mentally from these experiences.
I am legally blind, my dog is a teenaged, huge, strong.minded, powerful, entire male workinglines pup, with DARK nails, and still-- I trim em myself.
Get a little shot glass or chip-dip bowl, something low and small, filled with honey, molasses, margarine, PB, etc.. whatever disgusting, gross treat you can find.
Brush your dog into a swooning, relaxed, cuddle-coma, then...
Situate the dog in a corner, have the lights on full brightness in the room, put on your reading glasses, get your nail clippers, have dusgust-o-snacks nearby. Gently cradle or hold, don't grab too hard, each paw, and clip a nail at a time. After each nail, give a slurp of honey on your fingertip, or a treat of whatever you have. Praise! Kiss. Do another nail. STOP. Crate the dog for a comfy nap to process what just happened.
Next day: Repeat the process. Take the conflict out of this event for the dog.
If he or she initially tries to bite, go slower... try not to worry if she pants. This is brief, stay upbeat, give treats. If initially truly needed, muzzle the dog if you must.. a soft cloth muzzle lets them slurp the honey from your fingers thru the end opening. By the second or third clip-nail-and-get-treat game, no muzzle will be needed.