How fast can I make my swollen leg go away?

I agree. It completely depends on the cause. As dr. Isobe said, compression stockings can be very helpful. Short stretch compression wrapping can help even more but you and your doctor have to figure out why you have the swelling first..
Depends upon cause. Swollen legs may be simply due to prolonged standing and compression hose may help immediately. It can be due to heart or kidney disease, venous incompetence, blood clots, prior injury to the legs, and an evaluation by a physician is in order so that treatment can be started.