Try doing a search, its the large flashing red button to your right. But i'll also help:
I haven't been around a G audio wise, but I have done installs on other vehicles using the factory headunit. Normally you share a grommet through the firewall for the power wire such as the a/c line or the ecm wiring hole. Mine on my 240 is shared with the ac line. The power wire goes to the trunk via the best location, most of the time under the rocker panel covers. Use your adapters and run rca and remote wires from the headunit to the trunk as well, also under the rocker or wherever you choose. Next find a good ground in your trunk, wire everything up to the amp, then turn it on and enjoy!
