I did not take and pictures. The plastic box that the charcoal filter is in is easy to spot. It is about the size of a shoe box or a large loaf of bread and is just in front of the rear bumper between the frame rails. It is held up by four 10mm bolts, two on each end.
The small plastic box that is on the end of the charcoal filter has a baffle on the end of it and I bent it to one side to get at the felt filter with my neddle nose pliers.