I usually drip acclimate corals for about an hour. It's not strictly necessary, but I think it helps. Make sure you inspect the rock/frag for nasties like aptasia or nudibranches, etc. Whenever possible, try to avoid touching the flesh of the coral. It's OK if you touch it, but the coral will be happier if you hold it by the rock or skeleton (if it has one).
If you don't know what light it has been in, put it on the bottom of the tank in a shaded area. Leave it there at least three days, although a week is better. Move it up in the tank a few inches a week (or every few days), until it's in the right spot.
GSPs are well known for being cranky when moved. Don't expect it to open up within the first day, and probably not within the first week if you're moving it every few days.