Removing a 650 Yamaha Waverunner's Impeller/housing

I've googled and searched far and wide on how to remove the housing... no luck...

I've broken the 4 long/thin bolts at the threads... and removed the large bolts that fasten to the fiberglass frame. The pump assembly won't budge. Is the drive shaft c-clipped in somewhere?

I was pulling it apart because some debris stuck in the impeller... it obviously needs a rebuild.