I have taped my yorkie's ears first time at about 8 weeks. She didn't like it and tried to get it off. She succeed the first time. There is plenty of information on the internet about taping the ears and in the library books as well. You want to do it early on because when the dog is too old, the ears won't stand up anymore. It's always better for the yorkie to have ears up particularly because floppy ears are prone to ear infections as the air can't get in. I have taped her ears on two occasions 8-10wk old and they stood up within days. So it wasn't a lengthy process but it's different for each dog. Both of her parents had floppy ears that's why I knew she had to have them taped. You must shave the ear first...the hair should be fairly short...check this link for more.
How to Tape a Yorkie Puppy's Ears | eHow.com