Upgrade NAV2009 R2 to NAV 2013

Hi ,

I Plan to upgrade NAV2009 to NAV2013 , questions is :

1. How to get the / download software directly from microsoft Link ?

2. Can I Install it as Stand alone PC for trial . my PC has 32 Bit windows 7 pro. is it possible to install NAV 2013 ?

3. how to migrate my old database to new NAV2013  database .

4. I have some modifications tabel and code unit , should I Change it ? can I convert to NAV 2013 ?

if someone had exprience about it, please send me the steps to upgrade NAV 2013.

best Regards

Alfian