This only works from within an OU, it will not work via an AD Search.
1) Launch Active Directory Users and Computers (ADUC)
2) Go to the desired OU.
3) Select multiple users
a. Right click and select properties.
b. Click the check box of the field you want to change
i. Type in your information
ii. Click OK.
Obviously, only the properties shown on the tabs can be changed this way, so if the field you want to change is not there, this won't work for you in that particular case.
In that case I would recommend you download and use the AD Modify utility.
Introduction to ADModify.net
Article ID: 431, Created On: 10/8/2011, Modified: 10/8/2011