Nirvanaspartan

I got an extra remote transmitter, got it for free. Same exact one as my old one.Nothings wrong with my old one i just want to have an extra one, same FCC id number and everything i was wondering how do i program it so that i can use it on my car(doesn't say anything in my Honda Manuel) ? I still got the stock radio which i know you need to reset or set codes with, does it matter that it came off a different model? It was used on a civic, it works but my friend just got a better after market alarm , any clues? Like i said same FCC id number. Also i was wondering if you guys knew what the option button does on the remote