Cannot understand this one, air filter is not at all difficult to fit. Possible the snorkel refit is tricky after fitting the new filter.
You do of course have to remove the LH panel and snorkel.
If refitting is difficult do not try to do it flat on, the solution is to tilt the snorkel toward you, press the bottom of the snorkel flange to compress the new filter seal while sliding down to engage the lower hinge lugs and tilt to vertical before replacing the upper screws. It is a perfect fit"