Rename Client machine Computer name in a Server 2008 domain

Hi can someone advise me on how to change the Computer Name of my client machines connected to my domain controller (server 2008 r2).

I have about approx. 330 users, whose computer name must be changed since we are standardizing the naming convention. Is there a script on how to do all at once or doing each 300+ user manual one by one.

Thanks.