You
could do it yourself, but then you need to have some more experience with fish imo.
You need to know where to trim and how deep you can go without causing damage to the eyes or skin of the fish.
So look around, see if you can find a vet

In the end I doubt he's having that hard of a time, just take good care of the fish and try looking for some vets that may be a small journey away, or one that could come to your place and perform the procedure. That would be ideal!