I just joined here, and I need help. I am a new knitter, and am making my first shawl. It’s a really simple one, but I did discover a mistake two rows down on it. I am making it on circular needles, and need to rip out two rows. How do you do this on circular needles? I know it’s probably quite simple, but I just can’t figure it out. I know how to unknit, but that would take forever on this.