How to use disasm?

[fuusengum]

Hello, i read the instruction on README.TXT, it said :

First, you use disasm to disassemble Ragexe.exe:

	./disasm Ragexe.exe > disassembled.txt

I try to use it on cmd but it failed, i think i'm not suppose to use it on cmd, so how do i use this disasm command?