I was able to gently pry out the old "box" with screwdriver and using an old credit card to protect the door edge. It took quite a bit of prying around the entire area, but came off without a problem ultimately. It would have been easier to have a second set of hands to hold the unit while removing and reinstalling the wiring plugs from the old to the new, but I was able to do it with one person. Screwdriver helped here as one of the plugs had a small catch that needed some pressure to release. Snapping the new unit in was relatively easy, but had to pay attention to the overall alignment to be sure it was in the exact right spot before putting pressure on it to snap it in.
If you are careful and take your time this will not be a difficult install, just be patient as you are prying it out and snapping it back in.