To move multiple users from one OU to another:
1. Open the Active Directory Users and Computers snap-in, from Administrative Tools.
2. Double-click the source OU to expand it.
2. In the right-hand pane, Right-click the first user to be moved.
3. CTRL+Click each user, or if they are in sequence, SHIFT+Click the last user.
4. Right-click the last selected user, from step 3, and press Move....
5. Select the destination OU and press OK.