Don't bother with a kit, you've already got the polish so just by wet & dry paper instead.
If the swirls are deep enough, you'll need to wet sand them out. How deep they are will depend on what grade you start with but you want to work your way down to at least 3000 grit before going back to polishing again. Your starting grade will probably be trial and error until you get to the scratches, but you don't want to go any courser than you need to, to get them out. Buy a variety of grades from Halfrauds, start with the lowest grade and work up until the scratches start to look better. You'll probably need to go to a detailing place for 3000 grit though, I doubt Halfrauds will do anything that fine.
Then you'll need to re-seal them otherwise they've suffer UV damage again in a very short time.