Help me win $1000 fat loss contest.

[Acemanhattan]

My buddies and I are all formerly fit 23-26 year olds, who after a few years playing a bit too much poker, and drinking too much beer have all gotten a little squishy.
The bet: who can lose the higest percentage of body fat between december 1st and march 1st 5 of us putting up $250 each. I am not sure what my body fat% is right now, we are all having it checked monday. I am 5'10 175 and prob the second healthiest in the contest. 3 guys are about 6'0 200-280lbs and the other guy is an ex pro bike racer who currently is like 6'2 180. I basically just dont even know where to start. The biggest problem for me is that I am 3 months out of an ACL replacement surgery, so alot of lifting exercises as well as running are going to be out of the question. I wouldnt know where to start even if i could do those things. I am not incredibly out of shape, just the most out of shape ive ever been. I could still do 30 pushups and a few pullups, but other than that who knows. I thought i could put in alot of time on the stationary bike, and do some swimming at the rec center. What do i need to do gang?! I feel like i could get down to 155/160 but dont know how.