Don't use a bigger hammer! I did that last weekend and cracked a weld in the latch mechanism. I was working on the passenger door latch. I had the same problem. It turned out that inside the door skin where the striker protrudes there is a flange or another layer of sheet metal. In my case the striker was hanging up on it and would not slide out of the hole. I finally stuck a knife blade in between the latch and the inside flange and bent it in a little so I could lever out the latch. Of course the latch then fell down inside the door which added to the fun.

Good luck!

Wilber

Don't read the directions, that'd be too easy.