When you enter the Hadare factory having dropped the big boiler through the roof, after the FMV you'll find yourself in large enclosure with only one exit. Use your whip to remove the panel cover and crawl through.Go left to the control room where you'll be attacked by two guards, kick them around a little until they are joined by a third gaurd.Now two get all 'scaredycat' and run off through the doorway.Keep the third guard away from the door and kick him until he's in the room you first entered,Kick him into the pit!
This works in two ways,He is now trapped and you can kick him around the room to your hearts content will maxing out on all those yummy diamonds. Secondly, go back to the control room and whip all the switches etc. that show up on your cat sense, this causes a series of tall crates to move on the conveyor belt back where you started.The trick is to jump from crate to crate as they move,Tricky,aha but thanks to handing security guard, kick him across the crates path and they stop allowing you to easily hop across to the other side and the checkpoint.