Depends. Does the old fob still allow the car to be started? If so, you can start the car with the old one, wait 30 sec, turn the car off, immediately place the new fob near the ignition switch and start the car again and wait 30 sec before shutting it off. Some material says you can just turn to the "on" position instead of starting but I had a friend that actually had to start the car for it work....
If the old fob is not recognized by the car at all, you are screwed and need to have it programmed by the dealer or if you can find a locksmith that has the component to do it....
If the old fob is not recognized by the car at all, you are screwed and need to have it programmed by the dealer or if you can find a locksmith that has the component to do it....