I ran a search on the forum and google and neither came up with the answer to my question. My trainer and I have had several discussions about it, and we're both curious, we've only ever been around big horses!
I would like to add, I'm not asking so I can do this myself. I have close to no experience with mini's, and if I ever acquire one, it will most certainly be trained beforehand. I was just curious as to how it's done!