baseboard heat cover
I am assuming this is hot water baseboard heat. Trim off the panelling at the top of the baseboard shell with a utility knife. Then add a moulding, cove or quarter round to cover the top edge. It's a pain to try and unhook all of the fin tube brackets and then work the shell out from behind. Putting it back in again is just as bad. Plus, if you do get it out and then get it reinstalled, the shell will set back the thickness of the panelling closer to the wall. That means you have to watch whether your fin tube can move back that distance as well. Otherwise it may not hang in the brackets correctly.