If you want to understand about Webmaster Tools and removing URLS from Google then the best person to learn from is Matt Cutts. Matt is Head of Google’s Webspam Team and in this video he explains how to remove URLs from Google and how to prevent Google finding this in the first place.
If you listen to what Matt has said here you can help to optimise your website yourself.
If you need to understand how to build a .htaccess file then we can help here.
This page was Google Webmaster Help – Webmaster Tools Removing URLs