Here’s a small shell script for doing the recrawl process in nutch. You might have to change certain lines because I did some customizations, but it should work for you too
Nutch by default indexes the entire HTML document, this means that basically every single word of a page is taken to the index of it. When you have common boxes on your web site, e.g. a sidebar or a footer (applies to almost all web sites nowadays), nutch takes the terms of those common boxes [...]