I added cruise just about two weeks ago. It was a simple plug and play install. Remove the screws from your switch housing follow the wire down through the fairing. Unplug old wiring harness and plug new harness in. Reinstall scews. Take bike to Dealer, you will be charged 1/2 hour labor so they can plug the bike into the computer and enable the cruise. If you decide to have the dealer do it it will be 1 1/2 hours labor.
Just be real careful when doing the install for the little button switch for the brake light (in the housing for the brake lever) it breakes real easy and costs about 65 bucks plus an hour labor to install. It happenend to me, but dealer wrote it off as warrenty work.
Good luck, cruise is awsome on those long rides, helps out on the hand fatige.
As a last note you cannot set your cruise below 35 or above 85.