I moved my Steam games last week onto my D Drive. Steam has simple instructions on how to do this.
Navigate to your Steam folder. Make a backup copy of your Steamapps folder (just in case it goes belly up). Delete everything inside your Steam folder EXCEPT for Steam.exe AND Steamapps folder. Move whats left of your Steam folder (a bit lighter now) to your desired location. Run the Steam.exe . Voila !! Steam will now install all of your games on your other drive.