Step 1: Unscrew and remove vane inserts, remove plugs

Remove plugs that held old screws by squeezing with pliers to break away lip. Push remaining piece through with flat-head screw driver

Step 2: Install brackets

Put 2 of supplied brackets in the top holes of one side with screw holes facing you.

Step 3: Place mesh inserts

Place mesh inserts into bottom holes. Reach behind and while holding brackets, screw in the top 2 screws

Step 4: Screw top holes

Put 2 brackets in the top holes of second side. Place mesh insert into bottom holes. Be careful not to let the brackets in the top holes drop. Since you can no longer reach behind, use the short end of a small hex wrench to hold bracket while screwing in the last 2 screws.