May I suggest as a first step in your upgrade task using the UPGRADE ADVISOR
http://msdn.microsoft.com/en-us/library/ms144256.aspx
2. If you have "extra" hardware available purchase a copy of the DEVELOPER EDITION of SQL Server 2012 (available on Amazon.com for about $50 U.S. dollars). install it, and create a copy of the current DB and install same using the DEVELOPER EDITION as your 2012 Server.
3. Make the changes recommended by the run of the UPGRADE ADVISOR, RECORED / SAVE EVERY CHANGE[/B].
4. Then test the revised DB using a sample of typical daily activity ... updates/deletes/report/etc.etc. Make the necessary alteration(s) RECORED / SAVE EVERY CHANGE[/B].