To delete a person from the tree, click on the person and use the "Change or delete" button on the left. Note that you can not delete a person from the tree if that will result in other people no longer being connected to anyone else in the tree.
But you might be asking how you can leave a person in the tree, but not display any information about that person. To do that, you just delete the information (like names). Family Echo will then use a description based on relationship instead of the name.
