To transform myself into a strong, lean, scary fighting beast i would.....
 

........

(P.S. Please go into some sort of specifics here. The eat, train, sleep answer is useful but not really interesting reading)

serve 5-10 at chino or monroe.

Train in an athletically demanding combat sport 4-6 days a week... With a REAL team, and coach(es), and follow their directions to the letter...

Boxing, Muay Thai, Judo, BJJ, MMA... Accept no substitutes...

I think Dave probably has the most direct path, tends to look bad on the resume though.

Chuck's advice is dead on. I watch the transformation of guys all the time that come into the academy where I train and just totally change. Find the right team and you are squared away. The second part of the answer for me is to compete. If you don't say I am fighting / competing in X event on the 12th of July 2009 (for example) you really aren't as focused. Competition just drives me to train at the absolute the best I can.