If you haven't done it already, PLEASE be careful. Darren is right. use a sharp blade. if you cut too deep, the blade will act like a wedge and the brittle DP 95 can crack. I just carved the tvisor out of mine and caused a small hairline fracture near the bottom of the tvisor. luckilly it was easilly repairable, but the dp95 is so brittle, i could see how an accident like that could devistate a project.
good luck.