My company has been using TFS 2008 and Scrum For Team System V2 for a good while and we really like it.
Now we want to move to TFS 2010, but we have heard bad things about Scrum For Team System V3. Namely that it causes you to change your processes too much.
After looking at Microsoft Visual Studio Scrum 1.0 I think it is a good match for our processes.
How can I change my projects to use TFS 2010 and Microsoft Visual Studio Scrum 1.0?
What you need to do is setup your TFS 2010 installation. (As per the documentation). This can be a separate server (migration) or you can upgrade your TFS 2008 server. (If you upgrade the data in your Scrum For Team System V2 project(s) should be fine, but the reports will stop working along with the auto totals for bugs and PBIs.)
Make sure you install the Microsoft Visual Studio Scrum 1.0 template as part of your setup process.
Also as part of the setup you need to add the user that will run the rest of the instructions below to the Service Accounts Group for TFS. To do that see this question. (If you are migrating you may want to do this for both servers.)
You then need to convert/transfer your project(s) to a new project (and server if you are migrating) setup with the new template . To do this follow these steps:
NOTE: These do not have to be done on the server, any computer with access to them and an install of SQL Server 2008 will work. The computer you run on will have to have team explorer install for each TFS Version you plan to access. This means if you are migrating from TFS 2008 to TFS 2010 you need both versions of Team Explorer installed (the 2010 one is installed with Visual Studio 2010, but the 2008 one is a separate install).
NOTE II The TFS Integration platform does not support merging work items. So the Sprint Retrospective work items are created as a sprint. This is because the retrospective is stored in the sprint work item in Visual Studio Scrum 1.0. This means that for each sprint there will be two sprint work items. One for the actual sprint and one for the retrospective.
For this very reason I created a list of all of the ways that you can move from one Process Template to another.
Upgrading your Process Template in Team Foundation Server
I have listed #7 options for doing this with the Pros/Cons of each of the methods. I sympithise with you move above as I recently completed an Upgrading from TFS 2008 and WSS v3.0 with SfTSv2 to TFS 2010 and SF 2010 with SfTSv3 and it was certainly a process fraught with pain and suffering. After the actions described in the post it took me about 3 days of writing data manipulation applications against the TFS API to fix the data. Moving to Scrum for Team System v3 is a very bad idea...
The optimal solution for those circumstances is to use Process Template Upgrade #7 – Rename Work Items and Import new ones to change process template. This has all of the advantages and none of the pitfalls. I would however caveat that with "No one solution fits all" and I have recommended many option from the list above for different customers in different situations.
I recently created an Upgrading from TFS 2008 to TFS 2010 Overview, but I would recommend you read Upgrading TFS 2010 to TFS 2012 with VSS Migration and Process Template consolidation to see how that process works in practice.