Uhhh....obviously switching regs will not change the fact that the Fusion runs best at 250 psi, so yeah....take the stock reg off, screw the CP on, bottom it out at 0 psi, air it up and bring it up to 250 psi. I don't really see what you're asking....it's a pretty simple process.
I've found that my fusion does run best at around 260-275.
"And Shepherds we shall be For thee, my Lord, for thee. Power hath descended forth from Thy hand Our feet may swiftly carry out Thy commands. So we shall flow a river forth to Thee And teeming with souls shall it ever be. In Nomeni Patri Et Fili Spiritus Sancti."