Bend it a little more each time.
IF it breaks (snaps), toss it and start over. If the enamel flakes and you don\'t want to start over with a new grid, use your thumbnail to clear away any possible remaining enamel that might flake off.
i had so much trouble doing mine, i got my dad to come over to bend mine, he didnt understandd what i meant and managed to hammer and bend it into a U shape hahah its now a tunnel lol.