I have to update my tutorial but a better rule would be : all can be changed except the first byte and local vars (e*x).
So you get something like :
Code:
[0x55,0x8B,"*",0x81,"*","*","*","*","*",0x8B,0x4D,"*",0x53,0x56,0x8D,0x45,"*",0x57,0x50,0x51]