Cable clip question

That is a really big help. Great pics. No screws means I have to confess to trying for an hour to snap it on and failed. I remember popping them off with a screw driver but no luck snapping them back on. I kept thinking, there is either a trick to this I'm missing or...I suck. Guess ai know the answer to that. Taking Father's Day off and back at it Monday. Again thanks as I know I can't return until I get this