I second the advice of everyone here-I'd start gently manhandling him now so he gets used to being groomed and etc-we got Jaeger at 10 weeks and by his first vet appt he was letting me trim his toe fur, his nose fur, and letting me dremel his nails.
The moron vet tech was really rough with him, and he hasn't been docile about being handled since. I'm still trying to retrain him to accept having his nose fur trimmed and his nails done, and he is 6 months old now.
Also, a lot of groomers will immediately take a clipper to your dog because it is easier, which will change your dog's coat. Part of the fun of having a yorkie is watching the fur kaleidoscope