Re: 99 Windstar Remote
It's in the middle of the page on Page 98 of my Owner's Guide. My wife (the one that reads in our family) found it several years ago and programmed our remotes.
To reprogram the transmitters yourself, place the key in the ignition and turn from OFF to ON eight times in rapid succession (within 10 seconds) ending in the ON position. After doors lock/unlock, press any control on all transmitters (up to four). With each control press of the transmitters, the door should cycle (lock/unlock) to confirm programming. When completed, turn ignition to OFF. The door locks should cycle (lock/unlock) one last time to confirm completion of programming.
Hope that helps.