Hi, On my XJ the air box is a bloody great thing that gets in the way of everything when you try to work on the carbs, you can get it out but it is a right bastard to do, if you remove the carbs AND the carb mounting tube things (can't remember the name of them) you can draw the air box forward from it's place inside the frame but that's it you cannot get it to turn so you can remove it, I would suggest that you get a hack saw (no joke) and saw off the end where the air filter goes, other wise you can take the HEAD'S OFF to remove the thing but that is a bit extreme just to fit K&Ns to your bike, the ONLY way I have found to get it out is to take the engine out and that's just bloody ridiculous, as foamy say's tuck the breather pipe out of the way and it should cause you no problems but DON'T kink it, the battery box/tray thing is not part of the air box so you should be able to ignore that. It really is a stupid way to design something it looks like a bit of an afterthought