Fatal Error after installing plugin

I made the mistake of installing a plugin called GWPG3 (by digitaldonkey) on my site. after installation, I clicked the edit link and received the error below. I cannot get past the screen to return to the dashboard in order to uninstall the plugin. Can anyone out there help?

Warning: include(wpg3_class_WPG3_Xhttp.php) [function.include]: failed to open stream: No such file or directory in /hermes/bosweb/web234/b2344/ipw.themcgee/public_html/troop75/wp-content/plugins/wpg3/wpg3.php on line 640

Warning: include() [function.include]: Failed opening ‘wpg3_class_WPG3_Xhttp.php’ for inclusion (include_path=’.:/usr/local/lib/php-5.2.17/lib/php’) in /hermes/bosweb/web234/b2344/ipw.themcgee/public_html/troop75/wp-content/plugins/wpg3/wpg3.php on line 640

Fatal error: Class ‘WPG3_Xhttp’ not found in /hermes/bosweb/web234/b2344/ipw.themcgee/public_html/troop75/wp-content/plugins/wpg3/wpg3.php on line 427