How to change the language in Office 2010 from Spanish to English or viceversa
If you need to change the program language in Office 2010 then it is easy to achieve. First you’d need to locate the language pack and install it from the Microsoft website.
You can freely download ScreenTips installer which will translate your screen tooltips to any language. This tool is free and you can download it from here.
Changing Office language from any language to English
If you need to translate your Office 2010 to English language for menus, descriptions, help and everything, then you’d need to purchase the language pack in your language. Unfortunately there is no language pack for English if you have the Office version in any other language.
Changing Office language from English to any other language (ie: Spanish or Dutch)
In case you want to chance your Office 2003, 2007 and 2010 language to any other language rather than English then you can download the LIP package that is free. You can find a list of packages available for download in this page. If your language pack is not listed there then you can find more information about other language packs here.
The full Office 2010 language pack are known as LIP packages. These packages allows you to change the language for your Microsoft Office installation. You don’t need to install the application again, just the LIP package in the desired language. Here is an overview about differences on language packs.
Find more in Office Language options