For clarification, the wiring harness pops out of the clip to the lower - left of the yellow plastic clamp, and the yellow plastic plastic clamp SWIVELS upward so the wiring can make way for the filter to slide out.
Also, don't throw away the old filter until you remove it from the FRAME. You don't want to have to climb into the dumpster to retrieve the FRAME.
Some cheap filters don't fit the frame very well. You may have to improvise and modify the filter with a razor knife.
Pictures of the whole heater / frame / filter are found at www.hondapartsdeals.com