trying to program a ford keyless remote

Hi i am trying to program my keyless remote for my ford 2002 e-450 van. The numbers on the remote is FCC ID: GOH-3BFM2497, CAN: 1409 102 688. i have one remote that is programmed and one that is not. The keyless system is a ford installed unit.
Can anyone help.

Thanks
Mike

turn ignition switch on/off,on/off,on/off,on/off,on.
Making sure that you finish in the ON position-immediately press the lock button on the new remote and that's it. good luck jcglass

This keyless system is a ford aftermarket system. It was installed by a ford dealership as i was told. Someone told me it was a code alarm system or something like that. Can anyone help me figure out how to program my remote with this system?

thanks
Mike