You can grant the permissions using Active Directory Users and Computers using below basic steps:
- On the OU that contains your users, right-click and choose Delegate Control... , follow wizard
- On Users and Groups page, click Add and then enter SELF
- On Tasks to Delegate page, select Create a custom task to delegate
- On Active Directory Object Type page select Only the following objects in the folder, then scroll down and select User objects
- On Permissions page, select General, then scroll down and select Read and write Terminal Server license server