I don't know much about the '07 model but to put the Risers on my '05 was a *****. I wound up takeing the upper fork plate off to get the stock risers off. And the instructions from Rivco didn't state to "hold the riser from turning as you loosen the nut" because if the riser turns, it'll scrape the finish off the aluminum surface.
The instructions also stated the stock risers could be removed by turning the nut off the bottom but on my bike, there was no way to get to the nut. I've been turning wrenches most of my life & I've figured my way through some pretty tough situations but the only solution to this one was to remove the upper support.
I will tell you this, the "pain in the butt" install was worth it though. So much more comfortable to ride for long periods. One day Pianoman & I were on the Rocks for 12+ hours.
Good luck Seeya.
See ya.