Slow and low is the name of the game when working on geriatric horses. Most older horses are stiff to work on and some patience and attention to not causing resistance can help get the job done peacefully. If a farrier rushes the horse or doesn’t work with consideration of the the horse’s ability, the horse will get upset and that is often the end of the work to be done.
Many times, it takes several attempts to get the legs up to a working position. This is OK. I will often try to lightly stretch them in the process, which can help a lot.
I suggest asking your veterinarian about giving your older horse some bute or something before the appointment. Typically, a gram or two the night before and the morning of the appointment helps a lot.