The RS-BM500 shunt should be mounted as close to the battery as possible, and the remote display is intended to be mounted on a wall.

The following wiring diagram will be referenced in the next section.

Before doing anything, disconnect all wires from the negative side of the battery.
Cut the negative cable for the battery and crimp on new ring terminals. Alternatively, use a new wire of appropriate gauge to carry the full current demand of your system.
Install the shunt as shown in the wiring diagram above. Note: The negative terminal of the battery must connect directly to the“B-" side of the shunt, and there should be no other connections to the negative terminal of the battery for accurate measurements.
Use the B+ wire included in the package to connect the B+ terminal of the shunt to the positive side of the battery. Note: Do not stack smaller terminals under large ones.
Connect the shunt to the remote display using the included shielded cable.

Plan the location of your remote display and keep in mind there is a cable that needs to route all the way to the shunt.
Drill a hole in the center of the planned location and use the jig saw to cut a hole according to the following picture.
Connect the shielded cable to the shunt and route it such that you can bring it through the hole.
Connect the shielded cable to the remote and snap the remote into place.

Hold the "Ok" button for 3 seconds to enter the settings screen. The up and down arrows are used to navigate as well as change parameters. The "Ok" and "<<" button are used to enter and exit a setting.
Set the "CAP" setting to match the capacity of your battery or battery bank.
Optionally set the "HIGH V" and "LOW V" values to the voltages at which you want remaining capacity/percentage to reset to 100% and 0% respectively.
Alarm is the minimum Ah value that will trigger an audible alarm.
Once all of these settings are complete, hit "<<" and your BMK is set up.

Battery Monitors