knife/cog method??????

[Cza102282]

I recently was on a website which explained how to do this knife/cog method? I saw in the picture that there was a white cog behind the disc tray cover when you take it off. I took mine off and I can't see any white cog. So how do I do it?? Could it be that I was looking at a PAL version of PS2 while I have the NTSC and the only way you can do it is on the PAL version????? I am confused??? Please help me? Thanx.