Remote starter button

There are two ways to go, but some cheaper, lighter duty switches may eventually fail

The "low current" way is to pull off the yellow flag / spade "push on" connector at the starter relay, then connect the remote switch to that terminal, and to the large stud on the relay. It will not fire if transmission is in park (auto) or if you have a 70/ later car with clutch siwtch.

The second way, higher current through the remote switch, is to connect the switch to the large starter relay stud, and to the remaining large exposed "square" screw connector on the relay.

Also you can connect the switch directly to the only two terminals on the starter solenoid