taking apart engine.M#123k02,is there a trick to dismanteling.i can't remove bottom section.

Try this, buy some emery cloth, cut a strip approx 1 inch wide.
Remove the oil seal, you can pry it out with narrow bladed screwdriver.
Grasp each end of emery cloth and shine up the bottom of the crank all the way out to the end, removing all rust and crud, down as close to the sump as you can get.
shoot WD-40 all over the crank.
turn right side up and tap with rubber mallet all the way around the sump.
try to rotate the sump as you tap with mallet.
should come off.
hope this helps,
thanks,