If you build your family tree in Family Tree Builder, please read the following article: How do I delete a person in Family Tree Builder?
To delete a person in a family tree created directly on MyHeritage.com click on the person card and then click ‘Options’ > ‘Delete this Person’.
Please note that a scenario where the deletion of a person disconnects another person or a branch from the rest of the tree, is not allowed and the deleted person will be marked as ‘Unknown’ instead.
In this case first disconnect the person you would like to delete, from their parents, spouses or children, and then delete the person as described above.
To detach a person from other individuals in your online tree, please use the following article: