Front trim piece on the front top shell

[mmayville]

We are on vacation traveling the south to Florida and then to the Outer Banks in NC. While on the way to Florida I noticed an opening in the driver side top shell of my TM. Upon further inspection noticed that the trim piece used to seal the front corner had disappeared on the road. So I ordered a new trim piece and am now attempting to assemble a plan to put it back on the TM. Does anyone have the knowledge to assist me in putting the new piece on? When my TM was hit 2 years ago the RV repair shop put the new on the passenger side of my unit but I can put the one on the drivers side. It looks simple enough of just putting it on the unit and caulking the outside edges to the unit. My thought is do I need to caulk underneath before putting the piece on and caulking around the edges?