Try adjusting the title template in the plugin under the SEO > Title & Metas section to remove the site, sep and description.

For example, the Home tab title template should be simply %%page%% and for Pages under Post Types tab, it would be %%title%% %%sep%%  %%page%%

Visit the plugin’s Help tab under this section for reference of which quicktags to use to build your titles.

Our themes are optimized for stand-alone installs without plugins, so we can’t accomodate how every plugin works. In some cases, the plugin will not correctly override the theme’s title tag. In this case, you must remove the plugin title template, or remove the theme’s title tag.

To remove the theme title tag:

1. Go to Appearance > Editor and click on Theme Header
2. Find this code at the top:

   <title>
   <?php
   global $page, $paged;
   wp_title( '|', true, 'right' );
   bloginfo( 'name' );
   $site_description = get_bloginfo( 'description', 'display' );
   if ( $site_description && ( is_home() || is_front_page() ) )
   echo " | $site_description";
   if ( $paged >= 2 || $page >= 2 )
   echo ' | ' . sprintf( __( 'Page %s', 'ocmx' ), max( $paged, $page ) );
   ?>
   </title>

3. Replace it with:

   <title><wp_title(); ?></title>

4. or remove it completely