Study the below picture, which is also posted in the original thread regarding the Reverse function.
Once you remove the 12V DC socket assembly, located below the Reverse lever; you'll be able to get a better view of the Reverse module and the picture below will start to make more sense.
The entire module can be unsnapped from the panel for which it is affixed to; it's basically snapped on the outside of the compartment that houses the battery.
Unsnapping the module, will make it a little easier to land the DC cables on their appropriate terminal.
My dealership only removed the (+) positive cable between the Reverse Module and the Reverse Motor on my Model B; however, they removed the same (+) cable mentioned above, as well as the (-) Negative ground cable between the Reverse Module and the Transmission case on my R18 Bobber, which was a pain in the ass to get to the Ground landing point on the Transmission case. It required removing the heat shield, floorboard and the use of an extra long extension Torx tool.
You're going to need to remove the Engine case cover, which essentially houses the Starter motor and the Reverse Motor; this is also a bit of a jig saw puzzle... but doable...
