Just stuck mine new one on (didn't trust my old Sears one anymore), and thought I'd take some pics for those wondering on how to do it.

I did it the easy way using the clips. Gonna put the harness on when I replace the battery in the spring.
Grab the harness, do not connect it to the power unit yet.
First, hook the neg to somewhere on the block or frame. I used the already exsisting ground right in front of the side cover. This works fine. It doesn't have to be connected to the battery.
Hook the positive to the battery.
Smoke cigarette (or drink beer, or maybe both)
Plug yer power unit into an extension cord. Then, plug the harness to the unit.
The status lights are explained in the instructions. I'm not gonna type all that, so read yer own
Yer set for the winter then.