This is the source for the Floris Mod Pack.

The first thing to do, is to go to the folder Module Info and open the file info.py. Change 'export_dir_main_guest' to your MAIN warband folder, and change 'export_dir_custom_guest' to the foldername of the module you want to compile to (for example, 'Floris'). This folder must already exist (or you must create it).

You can find the source of all three Floris version in the folder 'Source'. You'll see there a few folders:
Files for Batch: just some python files used by the batch files. You'd rather ignore those.
Modmerger: The files used to add the source kits to the main source. If you create a new source kit, add that to modmerger_options.py.
Source - Floris Basic Mod Pack: The source files for the Basic version.
Source - Floris Expanded Mod Pack: The source files for the Expanded version. You'll probably interested in these.
Source - Floris Gameplay Mod Pack: The source files of the Gameplay version.
Source - Native Warband: The native warband source. The Basic version uses this native source.
Source Kits: Separate source kits that will be added by modmerger to the main source.