there is a hole near the bottom of right transom clamp. you can fit a large flat blade screwdriver though it and carefully unscrew the nylon manual release 3-4 turns. this will allow you to lift the engine by hand and get a block wedged up under it. the oil filler plug is on the front lower half of motor.
if you system is low on oil, then it has a leak. if it leaks oil out the it also leaks water in. it needs to be fixed.
On mine the release valve is around the side where the flanges meet. The fill cover is maybe 3/4" in diameter, is white and seen from the rear of the engine. And for most, full is even with the bottom of the threads of the fill plug....fill till it starts running out and reinstall the plug. Don't forget to resecure the manual release valve.
you can actually pop the orings and end up needing a rebuild if you run Mercury single ram trim with a loose MRV. Always tighten the MRV before running the trim motor.
