Look it up on you tube,thats how we learned to take Hawkies spurs off. You will be left with a quick that might bleed some. We put Hawkie in a cage for a few days after we take his off. They will grow back but over time they will get smaller.
I use dog toenail trimmers. If the spurs are too wide to get the toenail trimmer around them, I use the diagonal cutters I have for building cages to cut the spur. If you hold a flashlight to the spur, you can see the quick...it's the living part of the nail. If you can't see the quick through the keratin, cut about two inches away from the leg. That should be safe. After a few days or a week, the edges of the spurs will wear down and they will look normal-pointy again.
I think with spurs that substantial you are better off removing then trimming. We were nervous the first time we removed our rooster's spurs, but it is actually quite easy. Use pliers and then just gently twist them off. I then sprayed them with a vetericyn, and dabbed a little corn starch on an areas that was bleeding. There will be a little stub left that will regrow into a new spur. As in all things in chicken handling, I recommend doing it at night when the rooster is sleepy and easy to catch and work with.