Hi adpx17. Its a little bit confused at the start.
1. You put the file Tenka Fubu Launcher in Steam/SteamApp/Common/Shogun2 or whatever your directory is,
2. there are 2 folders inside the folder which are : encyclopedia and Tenka Fubu. copy the encyclopedia folder, paste on your Steam/SteamApp/Common/Shogun2/data.
3. finally, inside the Tenka Fubu folder are 4 files : 00Tenkafubu.mmi , TF_00_Main, TF_00_Main_12Y , TF_01_models, TF_02_UI. copy 4 files and paste to Steam/SteamApp/Common/Shogun2/data.
4. Clear enough?