How to remove the pulley????

Anyone know how to remove the pulley from the motor ,I am replacing
the AC servomotor of my Deckel Maho , they have sent me the new motor
but that is without the pulley so we have to use the old pulley but
that is so tightly fitted with the motor shaft that I was unable to
remove that with the puller , someone told me that this might
be "Shrink Fitted " with the shaft and can only be removed after
heating the pulley, is it true?
Please advice me what to do.

Thanks
Babar