A bunch of screws, a couple of tubes of silicone and a good drill/driver with a few spare batteries...
I have done a few of them. 901, 911 and 929's. If you suspect it is loose, it probably is. Make sure you go with bigger and longer screws, stainless steel ones. They arent cheap so buy the in bulk from a supplier, not from a marine store. The hardest part is getting the silicone to look good after you are done.
Mini
PS make sure you re-install them less than a foot apart and try not to re-use the same holes if they are "wallerd" out. You will find broken and bent screws. Dont be alarmed....it happens to alot of brand boats. Especially in my neck of the woods.