It depends whether you have a licensed product or a Cloud product...
You can swap languages/platforms for a latest licensed version product if you follow the instructions at the following link:
http://helpx.adobe.com/x-productkb/policy-pricing/order-product-platform-language-swap.htm l
Creative Cloud Help / Adjust the install language | Creative Cloud applications | CCM -
http://helpx.adobe.com/creative-cloud/kb/change-installed-language.html
