I haven't had to change my rotors yet, but I tried to pull one off the rear wheel when I was changing the tires, just so I didn't have to worry about bending anything, but my torx bit just started to twist so I left them on. I don't remember where I bought them, probably lowes/HD, so they weren't top notch stuff, but they were better than HF stuff. My front rotor is slightly warped and will need replaced before spring so I'll have to go get some better bits when the time comes.