Migration of Windows TSM server from 6.1/32bit to 6.2/64bit

[TSM]

Hello,

is there a description or experience, how to migrate a TSM server
from TSM 6.1 Windows 2008 32bit
to TSM 6.2 Windows 2008 R2 64bit ?

What are the steps?
Is it less risk to use separat servers?

Thanks in advance
Andreas.