I think that Tim the vibrac has answered the wrong question. From the picture I think that the question referred to the mod I have done to the kick start cover. I have just been and taken some measurements. The vertical distance at the rear of the cover between the top of the hole which holds the screw and the cut is half an inch. The vertical distance between the top of the kick starter shaft and the cut is one inch. Both measurement accurate to better than one millimetre. As for how I did it, I used a hacksaw and did it by hand. I am by no means a gifted artisan so if I can do it then so could anyone else. I used the straightness of the hacksaw blade to ensure the cut was straight, clamped the cover down to a solid surface and went at it slowly. Gently filed and/or sanded the edges to get rid of any sharp points. Although many people seem to think that it is an abomination to do this mod all I can say is that it has never led to any problems, with screws becoming loose or poor gear changes. It is interesting that, rather like the JE steering head mod most people never notice the change when looking at the bike.