I'm not sure of the thread, but I'll bet if you google/youtube you can find some good ways.
I happen to view a video on my pc about trick training by Shana (Clinton Anderson's protoge) but it wasn't really in depth enough to teach step by step.
I know that Stacy Westfall has a video about tricks and her horse bows so she can get on bareback. I'm betting it could be found on ebay
for fairly cheap or perhaps a memeber here (HF) would sell a used one. Maybe the library could find one through an inter-library loan servicen program (some libraries have this.)