2010 Toyota Prius, Audio Wiring

I'm trying to help my buddy out. He has a 2010 prius i think(is the same body style anyway), it has the jbl factory amp under the pass seat. What I'm trying to do is, use the factory head unit, factory amp, I want to grab 4 good line level out of the amp run them thru a loc then basically redo everything from there. I believe there are 8 outputs to speakers on this, I know the front door is woofer only. And the back is mids. If I can get 2 decent output with full frequencies that's fine, if i can get a mid/high, I can split that into the 4 channel aftermarket amp, and use the other for the sub, or once there rca i can do whatever from there. I trying to do this cheap for him, I'm giving him some of my old stuff, amps speakers, ect. Trying to do it for free. Not not spend $ on a dsp,ect just keep basic.

It might be easier to just throw in a different headunit, but even then I still need the 8 different factory location wire diagram if anyone has one? The rear doors might only have one shared wire not sure, don't know a lot about it. If it has ANC I would like to kill that in the process as well. He also had a speaker go out in the front and it killed the other side, not sure if it read a short and shut down or no ohm load detected, if I'm only using a cheaper loc is that going to cause any issues?

Worst case I can use a different headunit and run new speaker wires to all 8 locations.

Any help would be greatly appreciated. I have researched several hours and found very little. Thanks