I bought this on the advice from friends for an 07 YZ450F. The instructions were pretty straight forward, though I wasn't planning on having to drill the end cap before I received it. I had actually expected it to be pre-drilled for the specific model.. but it wasn't. Anyway, it drilled out pretty easy (I used an air powered drill and a quality drill bit). I tapped the end cap into the stock silencer housing (real nice fit) and drilled it in place. The drill bit listed in the instructions is about the same size as the holes in the silencer. I was worried the drill was going to drift, but the existing holes kept it all lined up. Once I drilled it, I popped it back out and cleaned up any shavings. Then put some high temp silicone around the edge and tapped it back into the housing with a rubber mallet. The Kit comes with self tapping hex key screws. They are a little tough at 1st, but no real issues on install. I was one screw short, but I may have lost it (I opened the packaging and they flew everywhere). I ended up using one rivet which I think is a good precaution. A friend of mine says he found one in the desert and he knows of another rider that has lost 2. He says he knows of a few people who just lost the end portion of the end cap (the part held on by 3 bolts). Loc-Tite is your friend people... I also used that on the self tapping hex screws.