Speaker wiring for kicker bass station

[Spacecrook]

2010 pathfinder LE with bose system. My friend bought a kicker bass station and improved his audio performance. My bose system is good but I thought I'd try it out.
I have the power hooked to battery but as far as the speaker wires I'm not sure the best place to "tap in". Same goes for the remote. I have bose amps under the seats. Don't I need to tap in to preamp speaker wiring? I can't distinguish the colored wires either. The back of bose head unit has no rca hook up.

I'm sorry, I searched around and couldn't find my answer. . I have pictures but don't know how to post. Thank you! !