They procedure is actually pretty simple, what you want to achieve is a tip that looks a bit like the tip of a drill with a small flat on the end about 1/32 inch in diameter. What is different is that the angle on the point is 90 degrees instead of 135 degrees, so the side angle is 45 degrees. You also want to hit the exact point where there is no drag while not allowing any fore and aft movement of the crane when it's closed and the screw is fully tightened.
Warning. Be very careful when tightening the screw, fully tightening this screw when it's not properly fitted can damage the stud on the crane. While tightening the screw test the crane for drag and stop tightening it if you feel the drag increasing. You've have it fitted when the screw gets tight just at the point where you feel just a hint of drag.
Tools. My preferred tool for doing this is a small diamond Knife Sharpener in a course grit to start and fine grit to finish. You can sometimes find these at a good hardware store. If you can't find them at your local hardware store, try the following 2 links.
Production Tool Supply
Production Tool Supply
One other tool that can make this task a lot easier is a collet type pin vise large enough to clamp on the head of the screw for holding the screw. These can sometimes be found at a hobby shop for model airplanes and the like.
Production Tool Supply
PS, the above items are quite useful to have in anyones tool kit. The Diamond laps last forever and do a great job on sharpening knives and that pin vise is also useful for holding very small taps or any small round part you need to hold firmly.