The ADM users and ADM URL are maintained within Dimensions, FocalPoint then picks them up from there.
To update the ADM URL:
Log into Dimensions.
Click System, Options, System Control Options.
In the URL of ADM webservice field, enter the new URL
Click Save.
To update ADM users:
Log into Dimensions.
Click System, User Records
Select the user
Select Options
Click the Set ADM User option.
Enter the required details
Click Save.