i used a cold chisel an hammer on mine. a little less messy than grinding, but i'm pretty comfortable with a chisel. it ended up leaving minimal marking after i used a file to smooth them out. maybe about a 1/4 inch each. then i just took some automotive touch up paint to it, wetsanded the whole thing, and we're good to go. of course a week later i found out that the bottom bracket had been installed wrong, and could not be repaired. it was a crap nishiki anyway. like one tin said, i'd be much more reserved about doing it do a de bernardi.