69 Charger quarter belt molding "C"channel

[mopar4don]

How do I get this piece on?
This is not even close to going on!
Do I need to trim the drip rail?

quarters and drip rail have been replaced

[hemi-hampton]

I see what the problem is. you said quarters & drip rail been replaced. if replaced with aftermarket parts thats the problem.

[timmycharger]

I don't love aftermarket either but I don't think that is the issue here.  Looks like the molding needs to just twist a bit and lock in on the top rail and the bottom should follow?

If the aftermarket panels were that far out, it wouldn't even resemble a Charger 

[mopar4don]

I did get this to go on. I first had to trim a bit off the end of the drip rail then what I did was attach the quarter belt molding to this corner piece and you kinda have to wrestle it around and pull it up and in.

I found this video showing how to get it on.
start at 8:25 into it

https://www.youtube.com/watch?v=lfYC3PsmR54