This is from the '98 manual. Your's is probably the same. Looks like a dealer, or shop with a DRB scan tool needs to make the change.
² Rolling door locks is a programmable feature of
the power lock system. This feature will automatically
lock all of the doors after the vehicle reaches a
speed of about 24 kilometers-per-hour (15 miles-perhour)
or greater. This feature will also lock the doors
if a door is opened, then closed again, at any speed
above 24 kilometers-per-hour (15 miles-per-hour).
The programmable features of the CTM can be
enabled or disabled using the DRB scan tool as
described in the proper Diagnostic Procedures manual.
Refer to Central Timer Module in the Diagnosis
and Testing section of Group 8U for diagnosis of the
base version of the CTM. For diagnosis of the highline
version of the CTM or of the CCD data bus, a
DRB scan tool and the proper Diagnostic Procedures
manual are recommended. The CTM cannot be
repaired and, if faulty or damaged, it must be
replaced.