Installing a powered subwoofer in a 2011 Honda civic, factory HU?

I'm installing a Sound Ordnance B-8PTD into my Honda's factory Head Unit. I was told that I will not require a speaker level converter since I do not have a built in powered amp.

Which wires will I need to tap into? I can't for the love of me find any info on an instillation without rca input/output and I would rather just man up and do this myself (rather than spend extra cash)

You need to use the speaker (high level) input option. The specs say there's a molex connector that plugs into the unit -- it will have bare wires that you'll use to connect to your factory speaker wires.

So you'll need to find the best place to access the existing speakers wires. In a civic I would think the rear speakers would be easiest. You do not need to interrupt the wires to the stock speakers. You can use t-taps or scotch locks to connect the additional signal wires for the amp, then route them from the connection point to the amp, and then make the connection to the amp harness. At the bare wire to bare wire connection you'll make at the amp solder and heat shrink is always best, but a much easier nearly as reliable option would be to use crimp caps.