I did this install a couple months ago. Getting the gasket off takes some time and more force than you would think, but follow the instructions. The toughest part for me was getting the carbon fiber piece over the fuel filler tube. No matter how many angles I tried I could not get it over it. Finally, I removed the two nuts that hold the tube to the frame, about 18" down from the top. That gave me enough room to wiggle the airbox piece over the tube. I wish that had been in the instructions. Also, make sure the part in the fender is seated fully. If not, the filler gasket piece (that you removed) will not set in all the way, then you will have to remove it again and make adjustments.
Typical install for the shade tree mechanic. It ended up taking me about 2.5 hours to do it. Now that I know how, I could probably do one in an hour. I was amazed at the change in sound I got. The sucking sound when your on the throttle is great.
Have fun. Let us know how it works out for you.