Hello Eric Krauska,
You need to move your 3.7 SP4 project to .NET 4.0, by applying the patch which you can find in your downloads page. After you make sure your project starts using .NET 4.0 you can create a new 4.2 Project, which contains the migration module. Then you need to follow the on-screen instructions.
You can follow my post in this thread you can find useful information.
Basically you need a fresh copy of Sitefinity 4.2 to complete the process. Once you have it set click on the Migration tool and follow the on - screen instructions.
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