Up gradation windows server 2008 r2 sp 1 (x64) to windows server 2012

How to up-gradation windows server 2008 to

windows server 2012

Main requirements

Processor :- 1.4 GHZ , x64

RAM: minimum 512 MB

Free hard disk: 32 GB

DVD ROM

Super VGA (800x600) or higher

Existing Windows O/S 1)windows server 2008 standard with SP2 to Windows server 2012 standard 2) windows server 2008 enterprise with SP2 to Windows server 2012 datacenter 3)windows server 2008 datacenter with SP2 to Windows server 2012 datacenter 4) windows web server 2008 to windows server 2012 standard 5)windows server 2008 r2 standard with SP1 to windows server 2012 standard 6) windows server 2008 r2 enterprise with SP1 to windows server 2012 datacenter 7) windows server 2008 r2 datacenter with SP1 to windows server 2012 datacenter

Active directory domain and services (ADDS) must be installed and configured

DNS Server Install and configured both zones

Functional level: windows server 2003 or higher

Global catalog enable

Full editions of Microsoft windows server 2012 DVD

Run forest prep or domain prep from DVD media