Originally Posted by bailsafe
Aha, this. I had to do this with my brake arm since I lack a vice grip.
On a side note, make sure your sprocket and pads are centered almost perfectly, the slightest deviation can cause some issues with the brake arm if you're not careful
Also if it isn't perfectly aligned it will cause a tighten and slack sort of problem on your chain. You think it's on there nice and snug, but on the other side of the wheel it'll be slack enough for it to fall off.