Adding Sound Ordnance B-8PT to 2012 Double Cab Factory

Thread title says it all. I want to add a Sound Ordnance B-8PT to my 2012 factory non-JBL system. Truck is a 2012 Double Cab, and I'd like to put the sub under the driver seat. Factory system sounds great for me, but I want a little more low-end (but not so much as to hear it from three miles away!) I'm not an audiophile, but I just want a little more.

I'm assuming the factory stereo has no sub outs. So, I guess I need some kind of converter or I need to tap into the factory speaker wires.

Anybody installed this sub in this manner? Suggestions? Things to look out for? Has anyone got the Master Sheet from Crutchfield handy?

FYI, changing out the head unit or speakers or anything else is NOT an option right now.

Any help appreciated, and thanks in advance!

 

I'm getting my 13' and this sub also looking for a response as well.