98 Altima Amp Install

Ive been trying to find a way to install my amp without having to go to circuitcity to do it. I've read posts about amp installs and where to do them at but does anyone have any specific help. I found where to go through the firewall underneath the steering column, the little oval of sound proofing that just pulls out. But how do i drill a hole through the firewall. IT IS IMPOSSIBLE to get a good angle and decent leverage. I'd also like to know how to connect speaker wire from the amp to the individual speakers. Thanks