Hi,
- download the modconfig.xml
- move/copy the modconfig.xml to the Config folder. The Config folder is at the same area where the safegames are. If you don't know at last at the windows version, you can open that location over the Rimworld option menu "Open save data folder".
- When you start Rimworld the mod should be loaded in the order the author of the modcollection setup.
IMO, 400 mods are too much !! :-)