If you need to delete a member from your team, you can do this by selecting "Members" from the drop-down menu to the upper right in your online dashboard.
Once you're in the members page, you will see a little bin icon to the right of every member you've added.
Simply click this icon, confirm and you will have deleted the member.
Bear in mind, you will not be able to undo this action. This means, you will no longer be able to assign jobs to this member and they will no longer have access to your account.