you can put the bootanimation.zip file in /data/local/ with rw-r-r permissions
the sound goes in /system/media/ as bootsound.ogg with the same permissions.
if you leave the bootsound.ogg file out you will have no sound. or remove/rename the one that is there.
you can also edit the bootanimation.zip file, in it is a description text file you can edit just remove the line that references the sound file
look at the boot animations section for tons of boot anis
I built a Tasker task to do all the file moving for me