Robert, there is a seal under each motor, where the motor shaft goes through the top of the lid. DO NOT take the nuts or screws out of the top of the motor, to try and get it off. All you'll do is diasassemble the motor, and cause problems for yourself. You cannot remove the motors from the top side of the unit.
The blue plastic lid has to be removed (turn off discharge seacock first) by undoing and taking out the 18 screws that go all around the lid. On the end of each of the motor shafts is an impeller that must be taken off. Then, you'll notice two globs of silicone rubber covering the two screws that actually mount each motor to the lid. Remove them.
The motors are secured from the underside of the lid, via the two referenced screws. Then the motor(s) can be removed. The seal is pressed into the lid from the top side. Remove the seal by prying it out with a small screwdriver. Clean the seat for the seal, and press in the new seal with your thumb (flat side faces out - spring side toward the inside). With a socket wrench of the same approximate size as the outer area of the seal, and a small hammer, tap it gently down, to be sure the seal "seats."
If it is an older unit (more than 5 years old), dribble a drop or two of "Crazy Glue" around the outside perimeter of the seal and allow it to work its way in between the outer part of the seal and the blue plastic lid. It only takes a few drops for each seal; it must run all around the outside of the joint where the outer perimeter of the seal meets the blue lid.
Allow it to set up for an hour or so, to dry. This will insure that water can't work its way around the outside of the seal, and get to the motor. Then apply a dab of SuperLube (or equivalent) grease to the inside of the seal, where the motor shaft will go through.
Insert the motor and replace the two screws. Then, using "Scotch-Brite" or fine sandpaper, rough up the area a little, where you will be applying the silicone rubber. Apply just enough silicone rubber caulk to cover the screw heads and insure that water can't work its way past them.
Then button up the unit and reconnect the wires. It's a little tedious, but that's the proper way to do it. Allow 4 hours for the silicone rubber to properly cure, before passing any water or sewage through the unit.
Replacement motor shaft seals, (1) required per motor, Raritan part # 31-102. While you've got it open anyway, it's best to replace both seals. Also, the black neoprene cover gasket is usually reusable, but if you need one, it's Raritan part # 31-112.
http://www.boatfix.com/bykeywordnew2.asp?textfield=31-102&texttype=2
http://www.boatfix.com/bykeywordnew2.asp?textfield=31-112&texttype=2
If the toilet is flushing with pure fresh water, you'll need to add 2-4 oz. of dry table salt to the toilet bowl with each flush. To initially commission it after servicing it, dissolve 1/2 lb. of table salt into about 1/2 gallon of hot water and pour that into the toilet bowl and flush the toilet. Then add 3 oz of table salt with each flush of the toilet from then on. If the machine starts to complain after several uses, increase the salt. If it doesn't complain, start decreasing the salt until it does complain, then up it just enough to keep the yellow light out, and you've got it. Use that amount of salt per flush and you should be fine.
