Drill the hole take your time do not force the bit. Use a center punch to get the drill to start and lube the bit and don't go like a bat out of **** on the drill these little bits will get mad and hot and break. Got on your safety glasses?
I'm deburring the hole do both sides, it won't take much and will save a little on cussing when trying to stick the cable through the hole
Cut off the head now. I'm cheating by using the dremel cut off wheel as you can cut the bolt with a hacksaw. I'm lazy and like my new toy.