So, the pulley was fitted after the motor was installed, so when it came to remove the motor the pullay had to come off first.
The easiest way to remove the pulley, is to remove the lower motor mounting and let the underside of the pulley rest on the top plate or on two bars placed under the pulley. Then use a small diameter rod or punch and gently tap the motor shaft to release the motor. Put something soft under the motor to catch it as it drops.
If that sounds a bit too much, you could try heating the pulley with a heat gun to increase the hole diameter, and using minimum force, try to gently pull the pulley upwards. However this is a bit risky, as there is the possibility of displacing the motor shaft from the internal rotor, causing it to rub on the circuit board.
A suggestion from a reader:
"I faced this same conundrum, and concerned with the bearings of the Papst Motor, ended up with a two step solution. First, I went to Ebay, and bought a small gear puller;, a Great Planes GPMR2410 Pinion Gear Puller with 2-5mm shafts The problem, once it arrived is that the base of the puller, which goes under the pulley, was too thick, and would not fit under it.
The second step was to make a thinner base, and was to go to the local hardware/building supply store, and get a fender washer, about an inch and 3/4ths in diameter, and thin enough to fit between the bottom of the pulley and the deck. I bought up a metric tap 5mm/.80 to match the threads of the puller's threaded legs, and with the right diameter bit, matched the location of the three threaded legs of the puller on the fender washer, drilled the holes into the washer, and then threaded the holes, along with cutting a slot for the motor shaft. It all went together perfectly, slid under the pulley, and within 2 minutes of completing the new base for the puller, the pulley was off, quite easily preserving the bearings.
Other choices could be toy train wheel puller, such those for for Lionel, American Flyer, and others. My concern was in bending or breaking the brass pulley, so I did not try them, as they only had two gripping points."
You could also make up a puller using a bit of brass bar a few cm wider than the pulley with a M2.5 hole tapped in the middle. Then using fishing line, tie it to the top of the pulley, taking 6 to 10 turns to either side under the top flange. Then screw in a M2.5 cap screw to bear down on the motor shaft and thus lift the pulley.
Here are pics of the motor as used in the Harman Kardon ST7 with the thrust bearing clearance screw easily seen in the third pic. (Note the sensible pulley diameter...) :
