Emblem for flip down gas cap

Hi, all.

My '67 has a flip down gas cap with the '68 emblem. As best I can tell the emblem is the only substantive difference between the '67 and '68. I've found a couple of sources for repro '67 emblems, but I can't figure out how I'm supposed to remove the old emblem since the little plastic posts appear to have been melted on rather than using the clips come with the repro parts.

So two questions:

Am I correct about the caps being interchangeable?

Is the best way to remove the old emblem to use pliers to snap or crush the backing, or should I use a soldering iron to melt it, or what?

Any help is much appreciated.

Thanks 2+2GT,

I'm thinking that I'd rather snap the "mushrooms." I never meant to use the soldering iron with the cap on the car, but I'm wary about the sorts of residue that might be on there.