1968 Barracuda Headlight Retainer Spring

The old adjustment screws were rusty and had a lot of play in them so I tried to install the new ones with the kit. It was a pain to get the old ones out and I had to mangle them. The new ones didn't just snap in as I assumed. I tried hammering them in until the plastic retainers inside the clips broke. I even tried taking the plastic retainer out and seeing if they will just snap in once the metal clip is installed, but they won't.

Are there any tricks to installing these? Is there a tool needed?