It's a good idea to acclimate them to the WATER, too. Even if both ponds are healthy, they will have different strains of "good bacteria" (and also "bad bacteria") in them. Colonies of fish become accustomed to the particular bacteria and water quality in the pond they live in. But new fish may not be adapted to those conditions.
So it's a good idea to gradually get them used to the new water. By quarantining them in a big tub with filter and air, in their original water, and gradually adding some of the water from their new pond. I've had brand new, seemingly healthy fish die for no apparent reason, most likely because they were not acclimated to some condition in the pond. This has happened more than a couple of times.
Also, I would suggest your friends get a few 22c feeders from PetSmart, and see how they do in the pond, before adding your older, bigger, much-loved goldies.
