Product review (4 stars): To install the two skinny strips of insulation, you ...
To install the two skinny strips of insulation, you have to remove the plate behind the refrigerator evaporator coil. First you pop out the bottom tray (which is the lower part of the plate).  Next, the coil has four tabs that go through the back of the plate and then bend to the side to secure it. The locations are near the bottom on the left and right sides and near the top of the left and right sides.  It's hard to see, so feel with your finger inside the left and right sides going up and down the plate and you'll feel the tabs. Bend them straight, then the plate should pop out behind the coil and you pull it down and out.