It is possible to unassign members and groups from the member management screen of YubiOn Portal.
A group is a feature that allows you to filter your members.
Click “Member Management” from the menu on the left side of the screen.
Click the member from the list of members.
Click the “Delete” button to the right of the group name in the group list.
Click “OK” on the confirmation message.
That’s all for unassigning members and groups.