We described granting this right in tip 3746 » How can I delegate the unlock account right?
and tip 3914 » How can I delegate the right to unlock locked user accounts, in a batch file?
To grant this right using Adsiedit.msc, a Support Tool on the CD-ROM:
01. Start / Run / Adsiedit.msc / OK.
02. Right-click the container or object that want to grant this right to and press Properties.
03. Select the Security tab and press Advanced.
04. Press Add and double-click the group you want to grant this right to.
05. Select the Properties tab.
06. In the Apply onto: drop-down list, select User objects.
07. Select the Allow box for Read lockoutTime and Write lockoutTime.
08. Select the Apply these permissions to objects and/or containers within this container only box.
09. Press OK, Apply, OK, and OK.
10. Exit ADSIEDIT.