Watch this video from This Old House to learn how to replace a baseboard heating cover.
1 Slide wood shims behind the back plate of the baseboard heater.
2 Use reciprocating saw to cut nails or screws holding back plate to wall.
3 Pull the adjustable damper from the hangers, and discard.
4 Prop up heating element, then use slotted screwdriver to pry the back plate from the hangers.
5 Slip the back plate out from behind the finned heating element, and discard.
6 Vacuum the heating element clean of all dust and dirt.
7 Slide new hangers behind heating element.
8 Mark the locations of the wall studs.
9 Slip the new back plate behind the heating element.
10 Snap hangers into the back plate.
11 Screw the back plate to wall studs with 1 1/4-inch drywall screws.
12 Attach the damper to the new back plate.
13 Slide on the end caps, flip up the flaps.
14 Snap the front cover onto the hangers; close end-cap flaps.