I need to know how to disconect the shift rod on a 1985 70hp Evinrude model #AE70tlcos so that i can drop the lower unit to replace the impeller.I have done one on a 1970 9.5 hp Evinrude where i could disconect it by undoing the bottom screw on the shift rod coupling which i could just see when the lower unit dropped down about an inch after i removed the bolts which were holding the lower unit to the exhaust housing,will the same apply here ? I would appreciate your help please...