You do not need to remove the top pully.
You can split the tranny with it in place/
They rust on sold and I oft need to press the pulley off the shaft.
It just makes it harder to get to the bolts with the pulley in place.
That pulley is easily bent and the shaft is held in place by a E clip so too much smacking will dislodge the clip . bend , break or crack the housing.
You cah heat it red hot if required then hit it with PB Blaster or similar that usually shifts stubborn shafts.
Rust disolver solutions ( not pastes or converters ) can also free it up