Quarantine for 6 weeks. These fish are susceptible to ich, and you don't want to introduce this into your display. It will tolerate hyposalinity, so if you want to treat prophylactically that's the route to go.
Put the fish into a display that is 6 feet long at a minimum, and that has rockwork set up to provide long channels for swimming. These guys are open water swimmers, and they get crazy (aggressive, even more ich prone) when crowded.
Feed veggies daily. Nori (unsalted) is fine.
Enjoy one of the most beautiful (IMHO) fish in the ocean.
mine wants to run the tank. it gives my triggerfish a run for its money, mine perfers to hang around rock work instead of using the swimming lane. but in all a calm slow swimming fish that eats all day.