LScript | simple object oriented language | Game Engine library

If you're referring to javascript files loaded by your template (as opposed to say an extension on your site), then the paths to these files are typically in one of your template's files.

There are all sorts of ways of building a Joomla template, and so these paths aren't specified in the same place in every template. But you'd always start by looking near the top of /templates/template-in-question/index.php

As an example, you probably have the Beez3 template installed on your Joomla 3 site.

Start by opening /templates/beez3/index.php, and if you work your way down from the top you'll find the Javascript files are loaded at lines 80-83

Instead of loading javascript files in index.php, some templates include them in a secondary file (often named 'params' or 'head' or 'includes') which is inserted into index.php.

Either way, start by scanning down from the top of your template's index.php file

Edit

Where is the source for $doc->_scripts stored?

Google if you want to know all the details, but most come from site-root/media/jui/ and site-root/media/system/

If you were to edit one of these files directly, there's the chance that your edit could be overwritten with a Joomla update.

A safer way would be to remove the js script you don't want, and then add a replacement.