Properly built Joomla modules extract their strings to separate language files to accommodate easy localization. They are stored in relevant folders and files in the /languages directory.
If for some reason you want to over-ride one of the strings, add a file to the /languages/overrides directory with the same file name as the original that contained the relevant string and put in the relvant string mapping into this file.
Joomla 2.5
Joola 2.5 includes a convenient facility for overriding text strings.
- Go to Extensions | Language Manager.
- Click the Overrides tab.
- Click New to add an override for that string.
- Search for the string name you want to replace.