Change shipping estimator window text

I have the free shipping module installed. Some of my products are via telephone so they have free shipping checked. However when someone buys one of these products, and they click on 'shipping estimator' the pop up window reads: Estimate Shipping Costs
Free Shipping - Downloads. How do I remove the word 'Downloads' as these products are not downloads.

Thanks very much.

Be,
The easiest way to find the .php file with the text is to use this:

1. admin panel/ tools/ developers tool kit
2. at the bottom search for part of the wording that is in the pop up shipping estimater..
3. Edit the file and place in your_template

I just did a search as you suggested, haredo, and chose all files lookup, all files catalog/admin. The result was: No matching Configuration Keys were found ... Free Shipping - Downloads. 'Free Shipping - Downloads' was my search term.

Any other suggestions?

I would still love some help with how to remove the word 'download' from my estimate shipping text box for free shipping products.

Anyone know how to do that?