My advice would be to fiddle with it some - it is fairly straightforward.

The main cover should be in two pieces - the larger behind the smaller. The small cover pulls straight up, being held by 4 spring clips over studs (two studs on motor, two on big cover). Once this is removed, the large cover is held in place with 4 to 6 cam clamps (and two tubes for air input, these just pull apart), and once removed the filters should be exposed.

Work slowly, and be careful about how much force you are applying.

-David