Kevin can probably speak to the accuracy of this, but I seem to remember sideplates are/were originally fit to the frame with a good whack with a babbitt rod. If that's the case, another whack will pop it right off.
Ralph Tremaine
The only thing I can say Ralph is it was hard to get off, the side plate and screws were heavily gummed up with old oil. I had to lightly tap the screw driver to loosen the plate screws even after soaking for 24 hrs.