Adding Keyless entry keypad

I used my buddies touchpad keyless entry on his explorer and now I want one. I found some on ebay and saw a DIY write up a while ago and want to try it out. What I’m looking for is someone that knows about how these work. I’m wondering if, when the correct code is entered that it just sends a 12 volt pulse like hitting the unlock switch in the door. Also can the code be reset fairly easily on these?