The thick part goes into the groove. Clean the groove as clean as you can. A folded piece of 180 grit or finer works well. Blow the debris out and spray some light lube in the channel. I use Rem Oil because I have it around for lubing guns.
Somewhere near the middle of the channel, there is an opening for allowing you to start one end and go to the right, then insert the other end to go to the left. Prior to beginning, use a screw driver to bend the metal at this opening to make insertion easier, then mash the metal back into place when you are done.
Carl
