CRM 4.0 SSRS question

Hello,

we have a CRM 4.0 Application, and there is a need to migrate the SSRS reports from SSRS 2005 to SSRS 2008. I am aware that I can do this with the CRM deployment manager.

If something goes wrong and reports doesn’t work, can I switch back to older version(SSRS 2005) after we have upgraded to SSRS 2008? Can you provide the steps i need to do that?