If you're using a Magento provided or custom theme - you can easily add the Localizer JavaScript Integration code by following the steps below:
1Login to your Localizer account and copy the JavaScript. (Menu > Integration).
2Locate the head.phtml in the folder view of your Magento Installation. It should reside at app/design/frontend/default/YOURTHEME/template/page/html/head.phtml .
3Paste the Localizer JavaScript directly above the </head> tag within this file.
4Save your changes to complete the integration and begin translation of your content.