Reprogramming keypad on the drivers door

To "reprogram" the code is only to change the "user code" which requires knowing the "master code" (factory set) which needs to be entered first. On the passenger side trunk hinge (open your trunk and look at the hinge/housing), you should see a sticker with 5 digits on it (with a Ford logo background) that is the factory code for the keyless entry. It is also found on the driver's side fender (mid-way down) as seen from the engine compartment. You are correct, after entering the code and holding down the last 2 buttons locks the doors. There is also a way to pop the trunk, and to open/close the windows after entering the code.