Had the same problem finding the info based on the instructions given. Maybe this will clarify:
1. Log into your Joomla Admin Panel
2. Click Components > Community Builder > Tab Management
Info: A list of items appears.
3. Tick the box for the item named "Menu".
4. Click the "Edit" icon at the top of the page.
Info: The "Tab Details" page appears. The right-hand pane is entitled "Parameters". The first field in the Parameters is called "First Menu Name".
5. Delete the info in the "First Menu Name" field.
6. Click the "Save" icon at the top of the page.
7. Check your site. The "About Community Builder" option should be gone now.
Hope that helps