To clear a jammed impeller:
Unplug the Pump.
Close the discharge ball valve (C).
Bail out the sink as much as possible.
Disconnect the union (Part No.5), unscrew the pump from
the sink tail piece, lower the pump to the floor, and slide it
out from under the sink (see Figure 3).
Remove the six housing screws (see Figure 4).
Clean out the pump. Make sure that the pump discharge is
clear. If necessary, replace the impeller.
Install the new gasket if necessary. Reassemble the
pump.
Raise the pump back into position, thread it back onto the
sink tail piece, and reconnect the union (Part No.5).
Plug in the pump. Run water in the sink until the pump has
run at least one complete cycle to make sure the pump is
operating correctly and there are no leaks.