On an Explorer I just bought, the hood only releases at the very end of the cable pull, so much as you need to flex the little handle inside past it's usual stopping point, I guess what I'm saying is if the cable is still attached, pull on it harder
At the same time have someone else kinda push/pull up and down on the hood where the latch is.
If the cable is broken, you have to get the lever that it pulls on up front to move to the drivers side of the truck(that's the way the cable pulls it.) This would probably be done with a long screwdriver or punch + hammer from behind the grill and would no doubt be tricky. + What Eddie said.