Kingdoms modding Setup?

I am going to be really annoying and ask a stupid question... What is the most stable/proper way for setting up mods in Kingdoms? I have been away from here for a while and have lost track of how to get things going. I want to make a mod for the Britannia Campaign. I have tried adding --io.file_first to the britannia shortcut, that seemed to work but I got the ui errors mentioned in another thread, I then unpacked the .sd files needed mentioned from that thread and got a CA_Lib error, so I had to re-install everything. Apologies for the long post.