How can I train my voice so I can scream like slipknot?

How can I train my voice so I can scream like slipknot?
I have A show really soon and I need this answered soon.
Every time I try to do the yell I pass out or get light headed.

erm I dunno actully,I just do it lol,
take a deep breath in tighting your throut and scream from the bottem of your guts.

You may have heard this before but just use your diaphram. It sounds like you are emptying your lungs completely, which is why you pass out (lack of oxygen). If you hold your abbs in when you are screaming then you can get more force without having to use all your breath.

get singing lessons and the way they make you sing will help u
honestly it helps me

thats sh*t. you can't really. it's his voice

Thanks the show went great I got it downpat now