I can't do it

what tool I should find to did it?

I think I used sandpaper, I folded it up so that it just fits and ran it through when I made this mod

Dremel if you know how (kind of dangerous)...sandpaper if you want to keep things safe and take a little longer.

I think I try to gind some sandpaper

that was better than dremel - -"

but thx ^^

Although this might take a little longer, it works. Simply just take a steak knife and stick it in the whole, and start twisting your wrist. This technique also works very well to make MX's too.