Change language in Wordpress template

I have a theme that is translation ready and already comes with Spanish language files. I need to convert my website from English to Spanish. I can give you my zip file that includes all files for the theme as well as the ftp information for the site. [login to view URL] Please reply with a price of how much this will cost. There will be more work in the future. Also I would like a brief summary of any changes you make to the coding, thank you.