If these are setup like the Strikers were (which it appear that they are) you would use a standard right hand bolt head. The lugs are machined into the action in a left hand configuration but the bolt head is RH thus giving you the left bolt right eject setup. With yours being setup from the factory as a 223 I would venture to say that you just need to change the bolt head and the baffle to a standard RH setup in the cartridge class of your preference and of course change mag as needed. At least that is how it should be barring any unknown (to me) variable specific to the PCS. Not sure why you would need to change the firing pin, however these likely have the newer style firing pins than what I have so maybe there is something there I don't know....