first, download hrimfaxihrimfaxi's v4 plugin files for KHBBS, its in the first post.
http://ifile.it/gia92rl pass: hako
extract the KHBBS folder to the root of your MS.
after that, extract the syslib.prx which is in the SEPLUGINS folder of the rar file into your SEPLUGINS folder (the one in your MS)
then, open game.txt in your SEPLUGINS folder (MS), add this:
ms0:/seplugins/usersyslib.prx 1
ms0:/KHBBS/KHBBS_patch.prx 1
then save it.
disconnect your USB. then activate the plugins in the Recovery Menu.
then start the game
yes, someone has already confirmed it.
if you already can play KHBBS from hako and you used the data-v4 plugin files, then you don't have to do anything but just to get the game in your MS