It’s stapled,only way to re-attach is to lift the rubber roof. I had to do this at the right rear of my unit because I struck a tree and bent a section.I removed metal strip on the edge roof. Lifted the rubber roof back,made a new edge from black stove pipe and screwed it back in place. ,counter sunk screws.
The edge from factory only has a couple of staples here and there holding this edge in place.