Mercury Optimax Models 135, 150, Direct Fuel Injection., Page 376Get this manual
RIGHT HAND NON-RATCHETING
5Remove gear housing from vise and re-position it as shownBe sure to use soft jaw vise covers and clamp as close as possible to water pump studs6Place block of wood on gear housing mating surfaceUse mallet and carefully tap gear housing away from driveshaft
CAUTION
DO NOT strike gear housing hard with the mallet or allow gear housing to fall