[AlexH]

1. Determine dia of motor shaft
2. Find drill bit of corresponding dia
3. Remove the setscrews from the pulley before drilling
4. Drill out hole on pulley
5. Replace setscrews and place on motor shaft. I often will drill out a small hole the same size of the setscrew in the shaft I am using it on, so it acts almost like a keyway. (Now I don't know how good engineering practice this is but it seems to work)