I'm sure you'll hear this many times -- word of mouth! I have a small retirement farm and I only have operated this way. I've had a couple of different trainers refer people to me, and some have come through friends of friends. So I'd send an email to everyone in your address book who is at all horsey in your area asking if they know of anywhere, as well as asking vets and farriers (although I know my farrier doesn't like to recommend places or people in case it doesn't work out). Also, if there's a pony club email list, tack shop etc. those are good places to post your query.
If you are in the midwest, I can't recommend Wyngate Equestrian in southern WI highly enough. It's a classy H/J/dressage barn but they have room for a few retirees. The BO treats my old boy like he's one of her own. He's so happy there - they helped me deal with the transition to being out on grass, and he's doing great. Tell me if this isn't the most contented creature you've ever seen:
(I love that picture!)
ETA I found this place when I put a query on a local forum (IL Horse) and the BO responded.
Don't wrassle with a hog. You just get dirty, and the hog likes it.