Not too difficult, at least on my previously owned 2016 ID.
Mine consisted of 2 pieces, a top and bottom. Each can be removed easily with a screwdriver. I only needed the top part but I could not find that anywhere so bought another whole unit, a Bargman unit. Sorry, no longer have the
Casita so can't look at it, but its easily found on Amazon. . Rather than replace the whole thing and have to recaulk the mounting plate, I chose to scavenge the top part and just replace that. I did have to snip some existing
electrical connections and replace them.