I have a 91 Honda. The vent assy is really simple!
First, check to see if there is schmootz i side your vents (squirrels, rats, etc). Soooooo easy on these models.
Take the exterior “dash” apart, as id replacing a windshield. Do t worry anout the “clips and round thingies” as you can get parts at zlowes (yes, Lowes, not a car parts store).
The venting system runs across dash and once you remove molding (as if replacing windshield) you will be able to,clean out the path.
I had a “nest” and could not get “them” to stop! Regardless of cleaning. When I disassembled exterior, I found a. Est i. The vent system. Removed it, filled vent system sith PEPPERMINT essential oil (I mean FILLED, like 8oz) and no trouble since.
Only way to get to the fresh air vemt sytem. Mine would not budge due to acorns in the lines
Great luck. If you need part numbers for replacing windshileld “caps”, i can provide. Just cut the old ones out.