Here is a quick rundown.

-Take off Neg from battery
-Find the rubber groumet (sp) that is on the firewall. Location depends on car. But there are already wires that run from inside the hood to inside the cabin.
-Put the power wire through the groumet.
-Pull the panels that hold the carpet down and run the power wire through to the trunk
-Pull your headunit and run your RCA and remote wire the same route as the power wire
-Find a place to mount the amp
-You can fuse the power wire again right before the amp, or use a fused distro-block
-Connect everything
-Fuse the power wire 18" from the battery
-Connect to battery
-Hook Neg on battery back
-Tune amp.