If your 2007 Bose amp is not a LUX version, you should be ok to bypass just the audio part. The LUX version digitally adjusts the volume, so it's not so easy. The Bose amp controls the warning tones, turn signal "tocks", etc. so removing it would cause you to lose them. Last I researched this, the way to do it is to disconnect the four audio channels going to the Bose amp FROM the PAC interface. So, while you have your console apart to remove the factory sub, you would cut the eight audio signal wires from the harness and solder or crimp RCAs to the ends. Then you could plug the factory wires with the RCAs on them straight to the 5-channel amp you're mounting under there. If your HU and amp controls the sub level separately ("bass knob"), you would just run an independent pair of RCAs from the HU down to the sub input of the amp.
I found a list of which wires were the speaker signals a couple years ago but it was for an '07 or '08 Silverado LTZ. I assumed the wires would be the same but I was gonna confirm later when I was actually working on this project. Maybe someone with access to factory wire schematics could pinpoint this for you/us.
