I just set up family share and my account is listed in my son's iCloud settings. How do I change this so he is the primary account on his device?
Assuming you are on iOS 8
Create separate Apple ID for each family member. Use this Apple ID to create individualized iCloud accounts. Use each account as the primary iCloud account on each family members device.
Choose which family member will be the family organizer. From within the Settings app on that family members device, tap on iCloud > Family Sharing > Get Started.
Sign into the Apple ID that will be used for iTunes and App Store purchases. You may be prompted to validate your accounts payment options.
Choose whether or not you’d like to share your location with your family.
Tap on “Add Family Member…” to start adding up to six additional iCloud accounts to your family share.