its in the PowerOff.apk in /system/app/
its a nightmare to mod (my opinion)
if you just delete the sound and resign the apk - you only get reboot with no power off
if you use a sound editor and lower the volume of the existing sound file - you get a screen glitch before shutdown - but it works
choose your poison i guess - sorry
the images are in that file too but are .pro extensions - gd lge!
Thanks for the answer!
so how do I edit the apk file and edit the sound file? Can I replace the sound with another one?