computer technology help

You have a forest that includes five domains and two trees. It contains the following domains:

Contoso.com                        3 Windows Server 2003 R2 domain controllers

Support.contoso.com         3 Windows Server 2003 R2 domain controllers and 1 Windows Server 2008 R2 domain controller

Sales.contoso.com              3 Windows Server 2008 domain controllers

Litware.com                         2 Windows Server 2003 domain controllers and 1 Windows 2000 Server domain controller

Partner.litware.com             2 Windows Server 2003 R2 domain controllers

What are the steps you need to promote the forest to the Windows Server 2012 functional level? 150 word minimum