Freezer coils were icing. Freezer would not cool properly.

I removed the shelves, then removed the cover in the back of the freezer that covers the cooling coils. There are two screws at the top and two at the bottom. I had to defrost the coils as they had excessive ice build up. Be sure to cover the drain hole with a piece of duct tape. After cleaning up the mess from the defrosting process I removed the two screws holding the defrost heater and bracket assembly, unplugged the wires on each end and hooked them to the new defrost heater and bracket assembly. Replaced the screws, cover, shelves and now it is working perfectly. Don't forget to remove the duct tape from the drain.