Jo
You've deleted lines that are redquired. I don't recall saying anything in the instructions about deleting ANYTHING :-) Although you are correct in removing the second and third sub-menus.
Put these lines back:
$submenu1 = WT_I18N::translate('Documentation'); //Sub-Menu title 1
$submenu2 = WT_I18N::translate('Forums'); //Sub-Menu title 2
$submenu3 = WT_I18N::translate('Cookbook'); //Sub-Menu title 3
Directly under these two:
// CHANGE YOUR CHOICES FOR TITLES:
$mainmenu = WT_I18N::translate('Blog'); //Main menu title
Then replace "Documentation" with "Blog"... and before you ask, yes, that will give you two entries for "Blog", the main menu and one sub-menu. That's how all webtrees menus work.
It doesn't matter what you give $submenu2 and 3 - they will not be used in your case.
I hope to have a new version of this add-on available soon, that will make configuring it a lot easier, and require no touching of php files :-) Sorry that its not really as "simpl" as it should be for now.