Man, I JUST replaced mine yesterday night and should have taken pics. That set screw is fing tiny. Once you pull the entire assembly off the bars you'll see the screw under where the reed switch goes into the brake assembly. It's about the size of .7mm mechanical pencil lead. Just a suggestion, don't do what I did......test the brake lights BEFORE you get it all back together. I had to pull the entire thing back off the bike for a small adjustment because my stupid azz didn't check it before hand,
That being said, it's so fing nice to have all the control buttons on the bike working, effortlessly, without 2-3 failed attempts and pressing super hard on the buttons to get them to do anything. I used to spend more time trying to use a turn signal than making the turn.