As the OWNER of the account, you can click on "My Profile" and then "Organization Settings."
To select a file from your computer, click on the grey upload button and “Browse” to choose a file.
If your image is not a perfect square, you will see the option to crop to logo by maneuvering the perforated square.
Once you click “Save” your church logo will be updated.
If you do not see the new picture appearing, you may need to do a hard refresh by keying in Ctrl + F5. You should see your new picture appear after the page reloads.