Introduction
Sometimes unwanted family relations such as Spouses or Children are added by mistake, especially when using the Diagram drag method.
Before removing these unwanted links use File > Backup/Restore > Small Backup just in case something goes wrong.
Details
The easiest placeAccording to GEDCOM, a Place should hold "The jurisdictional name of the place where the event took place…" to make these corrections is the Focus WindowThe Focus Window is the primary workspace window. It displays information about a chosen person, called the 'Focus Person'. introduced with V4.

Right-click on each Individual on the left, starting with the Children, even if they are an [unnamed person], and the menu will offer Delete Record and Unlink Record.
If certain that the Individual RecordEvery person in your tree will have a single Individual Record, which holds all the information about that individual that you have entered. You can view and edit Individual records in the Property Box Dialogue. can be unlinked AND DELETED then choose Delete Record.
Otherwise, choose Unlink Record and the Individual Record will be retained but unlinked from the Family.
If only one Individual needs to be repositioned, then note their Record IdEvery record in Family Historian has a numeric Record ID, which uniquely identifies it within its type of record. beforehand, use Unlink Record, and finally add them back as a Child or Spouse or Parent where required using the noted Record Id.
Before removing a Spouse, click on the blue bar that runs across under both partners to open the Family record Property BoxThe Property Box is the primary window for data entry and for viewing details of stored records. It is used with records of all types. . Clear any Status or Note entries. Then on the FactsFacts are one of the key concepts at the heart of Family Historian; they are how you record the things that happened to, or described, each ancestor (Individual). tab select each fact in turn and use the X Delete Fact button.
When the last relation is unlinked, usually a childless single parent, the Family will automatically vanish.
If the Family still exists with only one Spouse, then click on the blue bar underneath to open the Family record Property Box and on its All tab select each brown label on the left in turn and hit the Delete key.
Sometimes, just a single parent with children will remain and this can produce conflicting Diagram box presentations as discussed in the Related Forum Discussions.