Any advice for a mechanical moron getting ready to install the Rennline fire extinguisher mount?

Yup, just did mine.
Slide off the plastic covers on the front of the seat rails. Remove front bolts. They're a torx head bolt. Power seat forward and remove rear track bolts. Power tilt seat all the way forward, now shut off key. Lean the seat back and disconnect the electrical connector underneath. Lean seat back so it's back is resting on the rear seat bottom. You can now easily install the mount.
Only special tools are the ones for torxs sickets that hold the rails to the floor.
Good luck.