Need Advice! Trunk Won't Open!

ElFin said
Push down on lid, turn key until it clicks, and then release?

Yeah, turn the key and give the lid a whack. Pretend you're the Fonz, and when it pops open, hold your thumbs up and say "aaaaayyyyyyyyy".

If that doesn't work, call you car a nerd and climb through the back seat opening, like others have said.