I have heard so many horror stories lately, that I ended up buying a couple of grooming books and just trim/scissor Riley up, myself. I want to invest in a good pair of clippers and I still need to get a couple of videos.... but so far, he's really good and lets me do anything I want to him.
If you googled Yorkshire Terrier Haircuts and hit Images, a Ton of photos will pop up.
Good thing is, it will grow back.