Hope you have read how to identify URL parameters for exclusion through Google Webmasters Tool. Now let us see how to do it.
1) Log into your webmasters tool
2) Under Configurations , click URL Parameters
A common problem seen in mid to large websites is the custom or CMS generated URL parameters, which can increase the number of duplicate pages indexed in Google. As a solution, Google Webmasters Tool introduced an advanced feature – URL Parameters. The parameter settings are recommendations for Googlebot. If you want to make sure that BOTS follow crawl and index settings, use NOINDEX directive and robots.txt. They are more powerful.