In order to use a Switcheroo board with a remote control device, you need to connect it to the electrical switch sitting under the button you'd like to control on the device in question. This example shows how to measure switch polarity so you can properly connect it to your Switcheroo.
Step 1) Open the device, locate the switch.
Step 2) With the battery installed in the device, and the device turned on (no high power devices or devices connected to AC power sources!)... carefully measure the switch legs where they connect to the PCB. Be careful not to touch any other part of the PCB with body or voltmeter probes as you could get shocked and/or short out the PCB.
Step 3) Mark wires for polarity and solder ends to the switch legs
Step 4) Solder wires to Switcheroo output