i have a madd brake, and this guy i bought it from said it was grinded down, but when it came in the mail, it wasnt. luckily i bought it for only 2 dollars (LUCKY) but i need a way to grind it. right now im just grinding it against the concrete with my hands, and its slow, and tiresome. is there any way to grinding down without special equipment? i.e w/o a file, w/o a grinder, and w/o a sander