How do you reset the code for a key-less entry on the door of a 2000 Mercury Mountaineer?

its in with your spare tire its some numbers on the case some where

From inside the hatch the panel on the driver side just above the driver rear wheel is the security control model. there is a white tag with some numbers on it and those numbers are the factory key less entry code.

After you find the 5 digit factory code, punch in the numbers, then press the "1-2" button, then a 5 digit code of your choice. ( When i set my own, no lights blinked or horn honked, but still worked ) Next, open the door, and lock all the doors, and test your new code.