How to cancel Family Sharing?

The instructions to disband Family Sharing are in the support article, near the bottom of the page→Leave Family Sharing - Apple Support.

Note that if there are any children under 13 in the family group they must be transferred to a different family group before family sharing can be disbanded.

Read how to disband a family group --> Leave Family Sharing - Apple Support

These are the instructions:--> Leave Family Sharing

Regards

Giulio