i assume you're going to be doing a
Black Metal scream, if so then learn to do
Death Metal growls first, then just raise the pitch of the growl until you eliminate a majority of the bass in your voice... well that's what i do for a BM type vocal, but you could try to learn shrieking... which sounds like you're going to rip your throat out lol.
"Raise your swords up High!,
See The Black Birds Fly!,
Let them hear your rage!,
Show no fear!......Attack!!!!!"
- Amon Amarth, 
