Hey,
You have to go to Chadianzi Bus Station. I heard there are direct buses early in the morning, buy the ticket a day in advance. It’s something like 15-20 hours. I don’t know if the bus is to Seda or the buddhist Institute, however, tell the driver to drop you at the junction. Then take a shared vehicle to the temple (few kms.).
The trip pretty though, sometimes the road condition is awful, so if you have time I recommend you to go first to Maerkang (6-7 hours), sleep ther and then the following day up to Seda. This is what I did.
There is only one place to sleep in Seda, a hotel at the top of the hill. Spartan conditions to be called “hotel”, I stayed in a 3 people bedroom 40 RMB each one and I had to go to the public toilets because apparently the place didn’t have them.
The Wuming temple and the village is just gorgeous, believe it or not hasn’t turned into an Chinese tourism amusement park yet. I have traveled quite a lot and I can tell you there are few places all in the world like this one.
Enjoy it!!