The unbeaten 26-year-old will be making his first world title tilt in Detroit, Michigan and said that he is looking forward to winning the title on Alexander's home patch.
"It's the first time in my career I've been the underdog but it doesn't matter to me," Brook told Sky Sports News. "He's the champion and people are expecting him to keep the title but we know differently. I'm going to show him - and the world - why people call me the Special One.
"This is the fight, the one I've dreamed of and the one I've trained for and there's no way I'm not coming home without that title.
"Going to the champion's country and taking his title off him on his own patch is going to feel so good. It's going to be the icing on the cake going there to do the business."
Alexander's only defeat came to current WBO champion Timothy Bradley in January 2011.