Ford F-150 (2001) door check device: how do I gain access to back of door jam to remove and replace a front door check apparatus?

The passenger side front door check apparatus no longer prevents the door from fully opening, allowing the door to hit nearby objects or other vehicles.  I have purchased the part but have been unsuccessful in gaining access to the area behind the door jam.  I have tried removal of the interior kick panel and the fender well splash panel but have not gained access through either of these areas.