Upgrade SQL Server 2008 R2 enterprise edition to SQL server 2012 slandered edition

Hi everyone,

Need help on below concern.

I have SQL Server 2008 R2 enterprise edition installed. Which contains SSAS cubes, SSIS packages and SSRS Reports. 

I need to upgrade it to SQL Server 2012 Standard edition. 

How can I achieve this ??

And I don't have much idea in SSIS package migrations. 

Please help me to achieve this. 

Thanks,

Rohit