You have the ability to remove individual users from the network by going to the upper menu and choosing "Groups", and then "Members".
Once on the All Members page you have the ability to search for specific members by either first name, last name, email address or phone number. Once found hover over the individuals name and a three-dot menu will appear at the right of the row. Simply choose "Remove Member" and this will remove them from the entire network.
To remove a user from a specific group Click Here