Randy B: There are two set screws in each hole. The top one is a short flat bottom setscrew that acts as a lock screw. The bottom one is a longer tapered point setscrew that actually holds the cast iron pulley to the bearing. Get you some PB Blaster (avail at Wal-Mart & all auto parts stores) & soak those holes for several days (keep 'em wet). Then clean out the hole to get the hexhead (allen) wrench into the setscrew. When all six (6) setscrews are out then it will come off. Some times even then some tapping from the back side is in order because the cast iron pulley can rust to the outside of the bearing race... Patience & time will get you there....
Myron B
Myron B