It works as follows: log into our web site using the device you want to configure and go to the device setup help page (shown below on the left). Click the "Click here" link to download your custom profile. After a second or two you'll see it displayed, like the one shown on the right below. The profile contains all the configuration for your NuevaSync account. Click the Install button and you'll have a guaranteed correct sync setup.
Profiles are cryptographically signed so the green "Verified" will be displayed. The NuevaSync profile can be used alongside any configuration profiles your device already has (for WiFi or certificates for example). Note that the sync "account" can't be deleted in the regular way in the "Mail, Contacts, Calendars" setup page. You'll instead need to find the profiles section in the "General" setup page and delete the profile there. Apple has some documentation on how to install and remove configuration profiles.
