if you want to remove NAV Server Instances, then you can do this with the Administration Tool.
if you want to clear/remove NAV Server Instances from your database, then take a look here (Task 6): https://msdn.microsoft.com/en-us/dynamics-nav/upgrading-the-data
Answers
if you want to clear/remove NAV Server Instances from your database, then take a look here (Task 6):
https://msdn.microsoft.com/en-us/dynamics-nav/upgrading-the-data