Reprogram 96'keyless entry fob?

How do I reprogram my keyless entry fob for my 96 mustang?

in the left side of the trunk behind the panels, you should see a black box mounted inside there...there should be a gray plug that you will need to short accross with a screwdriver. Once you short the prongs in there, the door locks should lock...press the lock and unlock on your fob and the locks should lock and unlock again. Key fob should be re-programmed then...

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