Hi,
I don't recommend deploying/using the source code on production environments, thats what the pre-compiled "deployment" files are for.
The Visual Studio sln is configured for MS SQL to use other databases you would need to change the project references from MS SQL data layers to theMySql data layers for each Business project, there is no need to download the MySql dlls for use with the source code those files are only needed for the deployment package (not the source code package since it contains the source code for using MySql).
Hope it helps,
Joe