How do I remove a contact from a group?
First, go to the contact widget on the dashboard

The contact widget will allow you to remove contacts from a group. If you do not have a contact widget on your dashboard, you can add one from the widget dialog.
Next, select the group

This is done by clicking on the folder icon in the widget
Now, select the group you would like to remove a contact from

Search for the contact you want to remove

A blank search should return all contacts that are in the selected group.
Next, click on the checkbox toggle button

Check the checkbox next to the contacts name

Finally, click the button to remove from group

All contacts that were checked are now removed from the group. If you do not have permission to remove contacts, you will see an Invalid Permission warning.