Translate PHP/JS/HTML files in web application from English to Spanish

I need someone to translate the Help Center Live ([login to view URL]) web application from English to Spanish. This will involve opening every PHP, HTML or Javascript file in the application, locating all instances of English text, and translating it to Spanish (preferably, localized to Mexico's Spanish, if not possible Latinamerican Spanish is okay, but we definitely do NOT want it in Spain's Spanish). This application has about 190 translatable files, so experience with developing simple PHP application is a must as you'll need to know how web applications work in order to translate them without breaking anything. So, your job will be going through all the code of the application, translating all English strings to Spanish, and providing proof that the application works correctly and in the same way as the original version. I'll provide you with an environment to install and work on translating the application. This should be an easy job for someone who's native language is Spanish and knows how to develop simple web applications in PHP/mySQL.