what sort of filter have you got?
Is it a replacement panel filter element, or an induction kit?
If its an induction kit, it is usually just held on with a big hose clip, which you will just need a hose clip driver for, and then pop out the 2 breather hoses. This is what my K & N was like anyway.
If its a panel filter element (using the existing airbox) then you just have to undo the 3 plastic finger screw things, and unclip all of the metal clips surrounding the airbox. then the front cover comes of the box. You can now pull out the filter element and put the new one in.
Hope this helps.
Chris.