Defeating Leon
Stand near any ledge you can jump on. When you hear Leon coming, try to get him to hit the ledge and get stuck. Then, jump on the ledge, and simply keep hitting him with a melee weapon until he has been defeated.
Try to lure Leon into a maintenance room. Then, close the doors, and keep hitting him with a melee weapon until he has been defeated.
Get the motorbike from the front of the arena. Drive it to the fireworks store at Silver Strip. Get rockets and ride the bike to the alley with the maintenance room. Get a metal pipe and ride the bike to the rock canyon. Enter the maintenance room in the rocks and create a rocket launcher. Exit the door of the maintenance room and stand in the left side corner. Save the game. When Leon appears from the left side, he will run into the wall. Shoot him with the rocket launcher and repeat until he has been defeated.