If you think a Lhasa has lots of fur, try grooming a Collie!

My Sable and White Collie, Molly, didn't like to be brushed when we first got her. I brushed her everyday and now she's used to it. Like wolf_Q said, try some positive reinforcement with praise and a few treats. It will take time, but eventually she'll get better. Mine go to the groomers every other month, and I also brush them everyday. They get brushed approximately 15-30 minutes a day, using the undercoat rake once a week. No matts will be seen here!