Ok, first off, it is an excellent idea to trim spurs to save your hen's back, and it doesn't hurt the rooster at all. If you twist them off, they will still be sharp, so you didn't help your situation any. Just take a dremmel tool with a cut off wheel, or a fine toothed hacksaw to them. Get a firm grip on the base of the spur, not the leg, and cut the spur off about a half inch or so away from the leg. If you cut them too short, they will bleed some, but don't worry, it will heal fine. The goal is to cut the spur off just past where the core leaves off. After this is done, the spur will grow back, but will not be sharp. If you are still not sure, let me know, and I will gladly walk you through it, it's really no big deal. Good luck!