But there is an easy way available in magento. It has a built in function available in the Admin to allow you to do this without touching ANY code at all.
Just enable Translation in Admin and then you can rename anything you want without changing anything both for front-end as well admin!!
Go to [System] >> [Configuration] >> [Advanced] >> [Developer] > [Translate Inline] and change "Enabled for Admin" and / or "Enabled for Front-end" to Yes.
than click on "save config".
When you save a book icon will display on all menu items and most other text. Click icon
and a popup will show up which will allow you to edit/rename it to anything you want. The results are stored in Magento Translation csv files under your chosen Local and nothing is changed in magento core. Once you have complete all translations, change "Enabled for Admin" and / or "Enabled for Frontend" to No.
Hope it saves hell of time of all in finding which csv file in Theme is responsible for text changes.
