help installing driver side filler bar

The corner of my truck got hit and knocked out the lower filler bar on the drivers side. (the trim piece under the head light). I bought a replacement part but can't figure out how to put on the truck. I have tried snapping and sliding it in from side but can't get to fit. I sure there is some simple procedure so if anyone can help out I newbie I would appreciate it.
Thanks,
Bryan
(2001 2.7 SR5)

I can post a picture if that would help

 

I'm pretty sure it just pops on.

 

You sure the bumper/headlight is still aligned properly? Might be a missing bracket or something.

Check the other side to compare.

 

If everything is aligned right you just push it in from the front.