Removing the little firing pin assembly requires removing the main spring. This also is very easy, although it's a little more "dangerous" than removing the spring in a Ruger. The spring guide rod fits into a little hole on the front of the bolt, which you can just see in the lower left of the picture below. It runs along the length of the bolt and is held in place by its own spring tension. This is where it get a little challenging to put it pack together. The guide rod has to protrude all the way through the bolt in the front and it can actually seem like it's in place when it's actually not. The bolt will slide into place and appear to be correct, but the gun will not go back together completely unless this guide rod is properly "seated" in both the front and the back.
If you notice the detent in the end of the spring guide rod. This is used to remove and replace the spring in proper position. I used a small punch that fit into this detent (a nice touch my Smith, by the way) and just pushed slightly forward. The spring simply pulls out of the slot and then will "spring" backwards (to the right in this picture) to relieve the pressure and you can just pull it out. Very simple. Be warned, however, that if you don't "control" it when you take it out, it will shoot into the next county and possibly hit someone's Grandma in the eye. So be cautious!
If you notice the detent in the end of the spring guide rod. This is used to remove and replace the spring in proper position. I used a small punch that fit into this detent (a nice touch my Smith, by the way) and just pushed slightly forward. The spring simply pulls out of the slot and then will "spring" backwards (to the right in this picture) to relieve the pressure and you can just pull it out. Very simple. Be warned, however, that if you don't "control" it when you take it out, it will shoot into the next county and possibly hit someone's Grandma in the eye. So be cautious!