Its not as hard as you think. All you need to do is run a 12v source to a switch, and the other end of the switch to a junction on that black single wire coming off the starter. Check a wiring diagram first though, I dont want you to hurt yourself or the car.
you can buy a remote starter at most parts stores for about 10 bucks. just clip it to the solenoid and make sure the car is in neutral if you don't have to worry about the NSS