Dealers don’t rebuild shocks.Great question. I was talking to a rep with Zone (owned by same parent co as Fox) and he said he'd start at the dealer. I wouldn't trust the dealer to service shock internals.
When F150 raptors first came out, I replaced a set of fox shocks on one because the old ones were all torn up and leaking.I’ve emailed Fox but they weren’t helpful in that they needed a part number for the shock to know….