Are you talking about the screw set that came with the new P2 shell? If so, you can throw most if not all of those in your spares box and just re-use the screws from your P1 in the same locations...the mainboard and ESC's mount inside with the same screws as before and all the shell screws are the same too.
The P2 shell screw set is a near duplicate of the P1's, so unless you strip or lose any of your originals you probably won't have any need to break in the new set. Yet.