How do you bypass factory amp.

I have a 03 yukon xl with bose speakers. Aftermarket radio installed with a RP5-GM11 connected. Im going to install amp for sub, but i want to use head unit to supply sound to speakers instead of factory amp. I have looked everywhere inline and youtube, but no success. I am trying to avoid running independent lines to each speaker. I located amp under center console, not sure how to wire up to bypass amp.