I've decided to install an inner gas cap on my GT/CS but can't figure out how to remove the seal and spring from the existing cap. Anyone know how to do this?

Attached are a couple pictures of the inner cap.

what does this achieve????

what does this achieve????

It forms a tighter seal. The pop-off caps tend to let fumes escape after the gaskets get old and hard. Ford apparently thought so too, because their replacement service part was the twist inner cap with the pop-off outer cap.

ok let me know when you have it completed - seems like a good mod