Your talking about the batwing fairing right? Depending on what your goal is, mine was better wind protection, the Harley style and TUNES! I had to remove upper and lower fork covers,which required dropping out the forks from the triple tree. Buying "bagger" handle bars, metal pipe clamps from home depot clamped where the upper and lower covers used to be, and where the stock harley brackets will bolt to. I was able to reuse the stock risers but had to cut them down to fit inside the fairing, the front fairing the inner fairing and the vertical fairing brackets. you will probably need longer throttle cables, I had 10" higher than stock bagger bars I was able to reuse the brake line by re routing it. you will have to remove the stock headlight unless you want to cut out the opening in the fairing. there were a couple of personal websites showing how they did it and I copied their hard work. I will take some close up pics tomorrow and post them
Here are the Hard ware store pipe brackets that will let you mount a batwing on a vl800
next pic shows the brackets in place with the upper and lower fork guards removed and the cut down risers to fit inside of the fairing