Once the black tube is removed you can fit the K&N. I found it fit best under the tank if it was about an 1/8 of an inch or so behind the "nub" on the grey tube. Make sure the clamp screw will not interfere with and wiring. Secure the filter and gently lower the tank. Take time to insure there is room and that wiring and gas lines do not interfere with the filter.
Once you are satisfied with the fit reinstall the tank. It would probably wouldn't hurt to do the 12 minute tune. After the first ride or two check and make sure the filter is not interfering with anything and that it is still secure. Also be careful when washing and don't spray water up under the tank.
Now you have a nice little glove box under the seat.
Update: I have removed the tube that goes from the crankcase vent to the airbox. The K&N RU-1340 works for this application. Easier fitment can be had by unbolting and lifting the front of the airbox, otherwise it is very tight.