In Apex Automatic Traslation is not Possiable . We Need to Translate Word by word or you can dump application into a single file so than you can change the whole application at a time. But this will take some time depends on your size of application.
To Download application at a time
Go to Shared Components/Globlization/Translate Application/Download XLIFF Translation file from transalation Repository then download all the application totally and convert the whole application at a time then seed the application and publish Application.
You can follow the following links which may help you
Thanks & Regards