How to install floor mat retainer clip

I have a 2001 double cab and the mat keeps sliding so I bought the clips, but not sure how to install them. I tried to squeeze it through the hole and find the spot to pop in, but couldn't locate. Then I proceeded to remove the floor board plastic piece, but still can't seem to located the hole. Help!!!

 

If I remember correctly... There are 2 pieces to the retainer. One round piece goes under the carpet, which you have to remove door sill and get under carpet from there. Then the other round part goes on top and they clip together with carpet between, kind of like an eye-let. Then you just need to pop the hook into there and its secured.

Did you only get the hook part and not the metal ring???