or something like that...
1. Train well in advance of the farrier/ trimmer's visit - train every day and do it incrementally
2. Desensitise the legs first and teach the horse to keep them down when touched. (Buy a feather duster if you can't touch with your hand at first)
3. Teach your horse a signal to pick his legs up - squeezing the chestnut or tendon often works.Consider using clickered rewards to reinforce this.
4. Book your farrier/trimmer by TIME rather than by trim and pay him/her properly for that time. Booking a double or treble slot is well worth it.
5. Having trained your horse bit by bit to pick his feet up for longer and longer and in different positions. Ask your farrier/trimmer to put the horse's foot down after a set period of time if it is safe to do so - and then act as a timer. If the horse knows a release is coming, he won't feel the need to find his own.