I have Duo-Art XR grand piano, which I rebuilt and found that the
easiest way to remove the pump is as follows:

First I removed the electric motor.  I then used a medium size
automotive hydraulic pump jack with a wood platform about the size of
the face of the pump plate attached to the lifting arm of the jack.
The car jack can be easily rolled under the piano and raised up to
contact the face of the pump.  The pump holding rail can then be
unscrewed and the pump lowered.

I was able to remove the pulley so I merely placed a few support blocks
between the pump faceplate and the wooded support plate (this is done
to clear the pump pulley shaft).  You could cut smaller support blocks
which would go through the spokes of the pulley so the jack support
block again would be able to support the pump by pushing on the main
plate and not on the pulley.

Howard Towlson