the content in the login page can be changed under language management. Actually, where to edit that text is written on the login page itself...
You don't "change the structure" of the pages, you can change pretty much any label.
For your information:
this is the list of all the available tutorials viewtopic.php?f=2&t=11877
And here’s how you can easily google-translate them: http://itools.com/tool/google-translate ... translator