G'day speedy,
Yep, that airbox does have to come right off, as the reed plate is sandwiched between it and the barrel.
By the look of that IPL I've linked above, there will be two external slotted screws that go through lugs at the front of the airbox. As well as the two internal hex bolts, and the handle screw. Look at Fig 4 as well as Fig 1 to get the idea.