The thingy on the firewall is called the solenoid. On the toyota starters, the solenoid is attached to the starter motor. The FSM shows a wire that runs from the ignition switch to "terminal 50" on the starter. IIRC, this wire terminates at the starter using a spade connection. Remove that wire and connect one lead from the remote starter to the spade connector on the starter (terminal 50). connect the other lead from the remote starter to terminal 30, which is where the heavy lead from the battery is connected. When you push the button on your starter, power from terminal 30 will go to terminal 50 and the starter will turn on...