For grooming training, my first recommendation is not to force anything. Be assertive and don't give up easily, but make grooming a positive experience and be patient. Work daily with your pup, even if you are just going through the motions. Use treat rewards and plenty of praise. Pet and massage in between doing the undesirable stuff. I still do that.
I started with Max by holding and stroking him on my lap until he was relaxed (always choose a time when your pup is worn out from physical activity and isn't fired up
). Then I would introduce the comb. I used a tiny flea comb for the first few months. Gently I taught him to roll over on his back while I worked on his tiny face.
The process seemed impossible and hopeless to me even though Max had a good start with his breeder, but everything became easy in time.