Small Engines (Lawn Mowers, etc.): Ariens Belt Replacement, tight tolerance, shaft drive

Question
I am having a miserable time trying to replace the belts on an old (25+ years) Ariens Snow Blower from the top. (There is a plastic access cover between the motor and the chute.) Very tight tolerance between the pulley and the bottom inside of the base.  Should I try to remove the blower section from the motor/transmission section of the blower?  Any hints?  Thanks

Answer
i really dont feel that is nessesary. i know it is tight, but you should be able to work belt onto pulley, starting at bottom, turn  belt on by pinching it into grove. you may at least unloosen shaft drive baering retainer some to give you a little play, but to split apart????  i,d really try harder.