Item # 5 broke correct? Item 5 is the connector that snaps onto item number 1 (AKA connects to the orange O-Ring in BT's photo above.
http://www.mercruiserparts.com/Show...0&bnbr=240&bdesc=Gear+Lube+Monitor+Components
Depends on how much room you have to access the rear of the engine starboard side just under the water intake hose fitting if you need to remove the engine or not. I've been able to reach it working past the starter. Not going to lie, it's not easy.
Google the part number "image" to see how it looks and you'll see the clip you'll need to push on in order to release it from the fitting coming through the transom assembly (orange O-ring).
The fitting coming through should be okay since you see oil on the inside of the boat.
Chances are there is a piece left in the hose that you'll need to get out so you can put the new fitting in the hose then clip the new fitting onto the fitting with the O-ring.
Good luck.