How to find/change/delete index entries text in documents

Hi,

I have a catalog which contains alot of index entries. I'm using index to sort out all the products. Usually the index entry is "Name of the product" and if the product is "New", I'll add "Name of the productNEW" in the index.

So when I'm making the new catalog, I have to delete the old "NEW" texts in the index.

1. How can I find the index entries in the document (is there somekind of mark that can be found)?
2. How can I change/delete the specific text in the index entries?

Thanks alot beforehand to all who answers to this post.