my buddy form school challenged me to a fight recently which i accepted, now he is with all due respect a big fatass, about 250 lbs and in bad shape, i am about 150 lbs and in pretty good shape id like to know what the best way to condidtion myself would be so that i can totally take him by surpise and dominate him. any suggestions?

Conditioning is long and difficult, if you want to condition yourself enough to make a differance in a fight it might take you about two or three months conditioning every day.
But if you would like to make a start anyway I would sugest starting by using the flat palm of your hand to slap the area of the body that needs to be conditioned (Stomach/ Cheeks. Do not do it as hard as you can because if you break the skin or cause bruising the condition will have little effect. Instead of few hard slaps use hundreds of light slaps (Obviosly not too light) and this will condition your limbs to the fullest. If a bruise starts to come up use ice/ frozen peas because if that area is aloud to swell up the conditioning could be for nothing.