I followed the instructions in the manual and removed the shift lock lever screw, the 6 screws attaching the powerhead to the exhaust housing and the 3 rubber mount screws and it will not come loose. I was looking at Leeroy's Ramblings (Maintaining Johnson 9.9 Powerhead/Gearcase) and was wondering if his suggestion for separating the powerhead from the exhaust housing (using a sharpened screwdriver) should be my next step or is there something else I should try first?