OK, posting this up to remove any doubts and fears for anyone now or in the future about doing this yourself. It really IS simple, and with absolutely zero mechanical knowledge but a little common sense, you should be able to do this in 10-15 mins (depending on how many times you stop to take a sip from your beer/coffee).
Bear in mind, in this one I purchased the front half of the airbox, so I will show instructions on swapping that. If you didn't buy it, then you will CLEARLY be able to see what you need to remove from the stock box with a file (kinda wish I had done that instead of buying the box!).

OK, tools you'll need:
10mm socket, socket wrench, decent length extension for socket wrench (mine was a touch short, but flex-head on the wrench helped) and a standard philips head screwdriver.


Firstly, you need to remove the two screws at the front of the existing intake:


Then just lift the snorkel about 5mm and slide it straight out! Simple!


OK, now you need to remove the two bolts on the front and rear of the box: