#1
How do you take out the sound of a video? or lower the volume in the video ALOT?
Gear

Esp Ex-400BD
Jackson ps1
Dimebag crybaby from hell
Boss NS-2
Peavey xxx super 40 efx
#3
What software would work?
Gear

Esp Ex-400BD
Jackson ps1
Dimebag crybaby from hell
Boss NS-2
Peavey xxx super 40 efx
#4
You will need some kind of video editing software that can split the Video and Audio tracks apart.
The one that I use is Adobe Premiere. Expensive program, or free if you know where to get it.