I have got a 7928 Cobra car Alarm, I don`t know whether it is the same process or not but, here goes, (1) Prepare the remote by pressing both buttons until the LED on the remote stops flashing (10 secs). The LED should remain lit. (2) Press either of the two buttons on the remote, the LED on the remote will flash for 2 secs, The vehicle LED should flash indicating that it has registered. Repeat for all remotes.
Ian Percy
November 2007