I'd like to add a few things about the way I changed my cabin filter to this excellent thread.
1. Rather than completely remove the metal bar, I removed the 10 mm bolt on the right side and just loosened the 10 mm bolt on the left side. I then rotated the bar CW around the left side bolt until it cleared the filter.
I think the same kid that tightened the 10 mm bolt on the other Insight also worked on my car at one time. (Actually I imagine that the Honda mechanics are using their electric wrenches too enthusiastically.
2. There used to be foam weather seal like material around three sides of my white filter holder. The foam disintegrated as I removed the filter/holder from the A/C. Luckily I had some one side sticky foam weather stripping that I replaced it with. The foam I have is 1/2" wide by 3/8" thick. I think 1/2" x 1/4" on the top and bottom would be better though (and wider might be better too). I was able to get the holder back in with the 3/8" thickness but it took a bit of force to do it.
I didn't try to remove the remains of the original sticky (now hard) material. I just lightly wire brushed the areas enough to remove all the remaining foam. The sticky foam I had stuck to the remains OK.
3. Add a 10" piece of coat hanger to your tool list. Bend a short right angle bend at one end and a circle at the other end to hold onto. Use that to drag all the leaves etc from around the forward evaporator pipe (to the right side of the filter holder guide) so your vacuum cleaner can get them out of there.
4. After cleaning it I reused my filter, considering that I never cleaned/changed the filter in my '88 CRX for 23 years (if it has a filter). But whomever changed my Insight filter before did not install it correctly into the holder. The last filter pleat on each end of the filter is supposed to slip inside the white holder ends and into a slot towards the downwind side of the holder. One of my pleats was on the outside of the holder and the other one was crammed partially into the slot. So check that out.