It's basically the same procedure. When you "program" the remotes, your actually teaching the vehicle which remotes to pay attention to.
You have to find the Cobra's procedure details, but you'll be doing the same kind of thing -- getting it in learning mode and pressing buttons on the remotes you want the Cobra to use. When the procedure is done, the Cobra will ignore the other units. Nothing else needs to be done with the Ranger.
When you enter programming mode on the vehicle, the vehicle "forgets" all previously remotes it knew -- effectively erasing all the remotes from memory. Then when you use the new ones to teach it, it remembers only those.