I had the same issues as you, so I spoke to a mech. at my local honda dealer and got the low down on filter replacement.
1. Remove the Glove Box.
2. Cut the plastic stap over the metal band
3. Remove the 2 8mm bolts from the metal band (this exposes a cover on the heater core box, it is locked at the top and bottom of the Heater core box, removing this exposes the filter)
4. Remove old filter, insert new filter, with arrow facing left.
5. Install cover.
6. Install glove box.
This job took me about 20 minutes, the mechanic at my local dealer tells me that this job does not pay, so most mechs. do not like doing it.
P.S. my filter was VERY! VERY! Dirty.