Hey thanks for the helpful post. I used this info to clean my evaporator and there is definitely a noticeable difference.
To get the cover off of the evaporator box I had to cut it, because the copper lines were soldered into place after the cover went on. I cut off 2 small pieces and kept them. When I reinstalled the cover I put extra screws at the edge of the panel where I cut the pieces off, and aluminum taped the seams.
I didn't want to cut the triangle panel inside, because I wasn't confident about how it would hold up in a damp enviornment if I taped it back together. I was able to slide it off to the side enough so that I could get my hand in side and comb a lot of the lint off. Then I sprayed some foaming cleaner in there, hopefully it got off what I couldn't get with the comb.
Also, before I started the unit I took the cover off the bottom, and used a shop vac and to clean out the inlet duct. I also used some compressed air to blow out the fan. I had the shop vac running while I was blowing and got it to capture a lot of the dust that flew everywhere.