Guess I'll just kick this off, lol.
First thing I did after I jacked up all four corners was pop the hood and remove the heat shield. There are three bolts with some crazy @$$ heads on them, but they're not tight and can be removed easily with pliers if you don't have the right fitting tool.
Now it looks like this:
Then I went underneath and removed the underbody paneling. (I have an ECO) There are 8 bolts and a bunch of plastic pop fasteners (2 in each wheel well and one forward of each wheel well.):
This is the stock O2 Housing:
This is the stock midpipe:
Then I pulled the O2 sensor from the stock housing and opened up the V band clamp.
I didn't get a picture, but I removed the two bolts from the midpipe/resonator joint next.
Then, there are two brackets that the stock O2 Housing attaches to here:
It was hard to get to the aft O2 sensor, so instead of unscrewing it, I just unplugged it from the harness just above it. It was pretty tight with no lift, so I couldn't get a pic there either.
Stock compared to ZZP parts.
After that, follow the exact opposite procedure to put in your ZZP pieces.