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
