This can be done pretty easy. Just few simple modifications that you can even make in Plugins -> Editor in WP Admin.

1. First you should hide “View Project” button. To do this open wp-content/plugins/colio/grid.css and add “display: none;” to this style

.colio-view .colio-button {
  display: none;
  ...
}

2. Change mouse pointer when you hover thumb in portfolio. To do this add “cursor: pointer;” to this style in wp-content/plugins/colio/grid.css

.colio-list .colio-thumb {
  ...
  cursor: pointer;
}

3. Finally open wp-content/plugins/colio/colio.php and at the end (before ?>) add this filter

function colio_thumb_link($html) {
  $html = str_replace('colio-thumb', 'colio-thumb colio-link', $html);
  return $html;
}
add_filter('colio_item', 'colio_thumb_link');

Sometimes this may happen when Wordpress theme enables post-thumbnails for only specific post types, not globally. To fix this problem you should add the code below to the end of wp-content/plugins/colio/includes/post.php file

function colio_fix_featured_images() {
  add_theme_support('post-thumbnails');
}
add_action('after_setup_theme', 'colio_fix_featured_images', 99);