Lol with the state of those lines there’s no fuel pressure. That’s another fuel line under it. Can’t remember if it’s return or vapor. The original brake lines are just as bad, but looks to have new ones on top. Luckily it’s an errand truck. I bought it in january and I’ve put less than 200 miles on itwow that's a lot of rust. is that a brake line or fuel line under it?
either way, pinch it like Rhot said, or use needle nose pliers. If you destroy the plastic piece, no worries, autozone has them in stock. or does GM if you OE.. releve the fuel pressure first, or you'll have 50 psi of fun in your face