Magento to Magento Migration Tool by LitExtension allows you to migrate all data including Products, Customers, Passwords, Orders, Categories and Other Data within 3 simple steps.
This tool allows users to maintain all old url links of products and categories when you plan to replace the old store, thus helps keeping your current SEO ranking you have built up for years.
Module URL: http://litextension.com/shopping-cart-migration/magento-to-magento.html
