2003 GMC Sierra 1500 main belt pully removal

[dgbertrand]

Does the main pully that drives the belts coming off the crank at the front of the engine need a puller to get it off or does it sometimes just need a little tap. I got the centre bolt out but can't seem to pull the pully off. It doesn't seem to have a keyway on the shaft but not sure if it's tappered or not. PLEASE HELP ! The truck is a 2003 GMC Sierra 1500 4.8L 4x4 automatic with A/C

 

[98trck]

i thing there is four bolts the bolt the pulley to the harmonic balancer