In the interest of being thorough, I suggest you review the account's permissions in AD. Starting on page 21 of the View 6 installation guide you will see the permission requirements. Make special note of the additional items if you plan to re-use computer names. There is no need to remove the vCenter. Simply change the password in the Edit Domain dialogue shown below and you should be off and running. Run a test compose on a small pool, and/or create a small linked clone pool to verify. The worse that is going to happen is a few errors that can easily be fixed. Note: the format for entering the username should be domain.com\username.