I found the following in another forum on this site and they definitely work for the type of fob described which my Spacestar has.
central locking remotes(not alarm remotes) can be reprogrammed very easily.
press and hold both buttons on the remote until the light stays on permanently(usually about 10seconds).
this conditions the remotes for reprogramming.
you have to do all remotes when you do this.
next turn the key on to the run position.
then press the lock button on one remote and it should flash and go out.
then do the other remote.this should resynch the remote.
turn the key off and try.
if you happen to take too long between conditioning the remotes and reprogramming the light may go out on the remote.
simply press either remote button and the light should come back on solid again.
This will occassionaly work on the alarm fobs as well but most times you need the alarm code and the bullet plug for these.
hope this helps you all
AS AN EXTRA FOOTNOTE THIS ONLY IS FOR THE COBRA KEYLESS ENTRY REMOTE WHICH CAN
BE IDENTIFIED EASILY AS A ROUND BLACK REMOTE WITH A LARGE AND SMALL GREY BUTTON.
IT WILL ALSO HAVE A RUBBER TAIL IN WHICH TO ATTACH IT TO YOUR KEYCHAIN. (IMG:style_emoticons/default/banana.gif