I finally got the cover to this A/C blower assembly back on. The trick is getting it aligned in the back first. Then use vice grips to clamp the thing together while you get the clips back on.
Benefits of taking this off:
1) I was able to clean it out
2) I also replaced some sound insulation inside of it. The old stuff literally turned to dust when I touched it... Like this stuff:
Time for a break.