Currently, our company uses TFS 2010 and TFS 2012 RC. we need to upgrade TFS 2010 and TFS 2012 RC to the final version of TFS 2012 on different servers that people already use the TFS 2010 and TFS 2012 RC environment.
I'm not quite sure the question is here, so I will give you some links with information about the upgrade process. If you have specific questions, feel free to ask.
TFS Rangers Upgrade Guide: http://vsarupgradeguide.codeplex.com/releases
Official installation and administration guides: http://www.microsoft.com/en-us/download/details.aspx?id=29035
, : https://www.smashwords.com/books/view/181289
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http://tfsintegration.codeplex.com/
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