how to change backend databases sql server 2008 R2 to Sql server 2010 datacenter

Hi

i have current sharepoint 2010 form has backend database is sql server 2008 R2 on windows server 2008 R2 Enterprise

and this form has

1 application server

1 Search server (index server)

1 wfe server ( all web applications are running)

1 databse server

here  how i change this form back end to new windows server 2012 and sql server 2012 datacenter

adil