it gets pushed from the outside in , just take the guts out , flip it over and push it in.
One thing I forgot to mention, the rebuild kits include a new selector and selector center pin. The selectors have a square drive that fits into the pawl, and is held in place with a pin. This pin has to be mushroomed out on one end, otherwise it will simply fall out...I'm not sure how Snap On does it, I just tapped mine down with a ball peen hammer. The pin on the SL715 was actually a little longer than needed to be, so I had to cut it down a hair and then peen it over.