Install the F&L module using the zip file installation method. First, install using the Install version. Then unzip the Source version and copy all of the files to the F&L folder in the DesktopModules folder.
Then, you should be able to open the F&L module in Visual Studio and build it in Debug mode.
At that point, you should be able to use Attach to Process and attach to the w3p process and begin debugging the module. You can set breakpoints and trace executions.
Finally, using the .dnn file in the solution, increment the module's version number and start making your desired modifications. If you need resources for the whole process of module development, take a look at this thread:
http://www.dnncreative.com/Forum/ta...fault.aspx This tutorial might also help (even though the version of DNN and the version of VS may be different, the concepts are all correct):
http://www.dnncreative.com/video/ho...ual-studio You will find some other module development tutorials here if you search.