Download ADModify.zip and unzip the files to a folder in your path.
To Modify Active Directory Users:
1. Launch ADModify.exe.
2. Verify that Modify Existing User Attributes is selected and press Next.
3. Select a Domain Controller from the drop down list.
4. Find the OU/Users you want to export, select it, and press Add to list.
5. Select the users to modify from the list on the right and press Next.
6. Find the field you wish to modify, type in the new value, and press Change.
NOTE: Any modifications, successful or not, will be logged to <location of ADModify>\admod.log.