I caution you with a horse like this. I owned a gelding several years ago who became extremely dangerous he was so sour. After working with him for a little less than a year, and spending more time in tears out of sheer frustration, I ended up selling him to a dude ranch where he was in his glory, (with his nose constantly shoved up the butt of the horse in front of him!) However - what I still have as a constant reminder of my "struggles" with this extremely herd bound/barn sour gelding is a torn ACL, and probably arthritis in that knee before long!! Think long and hard about trying to reform this horse, and whether it's worth it!