There are a lot of threads on this subject but you need to replace your upper fairing brackets with the 2010 brackets to use the vented fairing lowers. The 2010 bracket will raise the upper fairing and tilt it back some and they were designed so the vented fairing lowers could be installed on the RG.
The 2010 RG was the first year RG that had the vented fairing lowers, 2009 and earlier models need non-vented fairing lowers that were RG specific.
The 2010 brackets don't cost too much you will need the main fairing bracket that attaches to the frame and the left/right fairing support brackets that attach to the crash bar.
I did this mod to my 2008 FLTR and it is well worth it. JMO