Problem with installing the plugin

This is the error. What can i do?

Fatal error: Cannot redeclare wp_smush_rating_message() (previously declared in C:\domains\blown-twisted.nl\wwwroot\wp-content\plugins\wp-smushit\wp-smush.php:73) in C:\domains\blown-twisted.nl\wwwroot\wp-content\plugins\wp-smush-pro\wp-smush.php on line 88