Let me try it then.
By prebuilt websites, they mean DEMOS, like every themeforst theme author claims if they have built premade demos.
I looked at your guides for integration with other themes. INtegration seems simple.
Also, after having a look here https://forum.muffingroup.com/betheme/discussion/2148/removing-be-theme-logo-from-menu
Especially his comment @
<?php if( function_exists( ‘ubermenu’ ) ): ?>
<?php ubermenu( ‘main’ , array( ‘theme_location’ => ‘primary’ ) ); ?>
<?php else: ?>
<?php if( mfn_header_style( true ) != ‘header-creative’ ) get_template_part( ‘includes/header’, ‘top-area’ ); ?>
<?php endif; ?>
See, how the author/user managed to change the theme for uber. I hope you can get a better clue than me, as i am dummy for programming.