I do have a recommendation at the bottom.
I have the Harbor Freight setup, and two caveats here: I hate all things Harbor Freight -- if anything I need involves something other than a solid piece of metal -- I will not buy HF, and; I bench press 70 lb on a good day . . . when I played little league as a kid, when it was my turn to bat, all the outfielders would move in.
Your results may vary.
I had a Honda ST1300 before the Rocket, and one time I invited the guys over to my house for a Maintenance Saturday. Among other things, I made the tire changer available, and I needed to replace both tires on my bike.
I don't doubt that there are tricks one can learn. A visit to the Army tank depot in Anniston, AL is illustrative in that there is a wall where are stored the tools used by the women who assembled and worked on the tanks during WWII -- mostly long lever arms adapted to various tools.
The short of it is, I could not, even with soap, muster the strength to slide the bar around, and the knowledgeable mechanic who was assisting us that day, took the wheel off the changer, and changed both tires sitting on the ground with wood blocks to keep from marring the wheels, and using big steel levers - big daddy versions of what folks use on bicycle tires.
For me, I'm in the camp I do it seldom enough it's worth it to pay someone.
That said, one device I *can* recommend, is a neat little balance tool, so if I remove the wheel and take it to someone to change the tire, I will balance the wheel myself before it goes back on.
http://www.marcparnes.com/Triumph_Motorcycle_Wheel_Balancer.htm
This guy makes the cones himself, so even though he doesn't list the Rocket, he either has cones that work, or will work with you for a small fee to take your measurements of the inside diameter of both sides of the hub, and ship the two cones to you.
His concept is simple, and well executed. One finds a way to support both ends of the balance bar, carefully ensuring it is level, then placing the bar through the hub and snugging the cones so that the bar is centered in the hub, then placed back on the support. The bearings at either end of the balance bar allow the tire to swing freely, and Marc supplies lead disks with sticky side and keeps placing them opposite the low side until the wheel is balanced. Works like a charm.
I note others use Harbor Freight changers and Marc shows an HF upgrade on his site, though I cannot speak to that.