I put a performance sway bar on my 06 GL and 2012 HT1800 Roadsmith.
The complete job took about 45 minutes start to finish. Here are some pictures of the job. You will need to jack it up and take off both rear tires and wheels. There are only 6 nuts and bolts to take off it only takes 2 - 9/16 and 2 - 1/2 inch wrenches and it slides right out through either the left or right side fender.
I can only submit 10 photos so hope you can all get the idea if you decide to do this yourself.