Installation in a new folder

I need to translate the entire web site into English (currently its in Serbian) and i’m struggling with the task.

I’we tryed to work it out with plugins like wpml and qtranslate and haven’t had success.

This is what I would like:

A new folder: lets say http://www.example.com/en, that would contain the english version (i would create links of course to navigate between the languages). What are the steps to achive this? Do i install a new wordpress installation into a new folder and have two databases? I would like the keep the theme i am using exactly the same while only changing the pages to english (i manualy translated everything already and have the files on standby).

Please help and thank you in advance.