Your 9.2 pack should be a bunch of .cia files. You should put them in "sdmc:/updates/<your 9.2 update files>.cia"
Also, you need tux's sysupdater app in: sdmc:/3ds/sysUpdater/sysUpdater.3dsx/.smdh
You can get it here:
https://github.com/TuxSH/sysUpdater/releases
Use browserhax to set up menuhax (Install, create config file type 1, no input code) and reboot without pushing any buttons.
Once in menuhax, run FTBrony, close by pressing B twice, then run tux's sysupdater app.