How do you put in a radio code?
 

I'm not asking for the code, I have the number to call to get the code, my question is how do you actually put the code in? Is there some sort of additional handheld device I need or what? See here is what happened, I bought an eclipse with the inifinity sound system and a busted cd player. I didn't want to go to all hassles of aftermarket so I bought a similar infinity unit off ebay out of an eclipse with all the matching plugs and everything. Since installing it my alarm goes off everytime I unlock the doors. I am ASSUMING its because a new security code needs to be put in. If that is not the case someone please let me know otherwise. If that is the case if someone could inform as to how to do this I would REALY appreciate a little help. Also, whatdo I tell them when I call the number to get the code?Thanks in advance!!!