Automatically Print Both Sides with HP LaserJet P2015dn and Window 7

Since i upgraded my laptop with Windows 7, i couldn't figure out how to automatically print in both sides with my office's HP LaserJet P2015dn. On windows XP and Vista that had "HP LaserJet P2015 PCL5 Plug and Play Print Driver Package" HP drivers installed, there was an easy-to-find-and-understand option (Two-sided Printing) on Print → Preferences → Printing Shortcuts tab. Unfortunately, on Windows 7 the only driver available is the one coming with Windows 7 but there is no such tab and the closest option to it, is to print duplex manually.
Today i tried to fix this, but having spent allot of time using the good old fashion way of trial and error, I decided to call HP's support. They tried to help (not that effectively) but i managed to find the solution by my own while i was waiting for reply...

So here are the steps to fix this: