Pull the pin at the back and the breech is then unlocked and you flip it over and remove the bolt, did you actually mean that or did you mean the hammer
Hammer removal is by taking of the back plate and then removing the ram then prising the hammer from the shaft (it should be locktited)
you will of course need an Angel tool kit to remove the ram and re-adjust the snap ring
Grip frame? may have something to do with the flash tank tube holding the grip frame but not 100% sure