^ yup! That's correct.
If you've already setup the phone using a normal gmail account and you want to use your google apps account, you'll need to start from scratch. That means every customization you've done so far,
will be lost.
- Go into settings
- Go into SD car & phone storage
- Touch Factory data reset
- Confirm
- Reboot
- Use your google apps login
- Don't press enter. Simply click into the password field
- Enter your password
Hope that helps