Are there any tricks to replacing the oil seal PN AP2045443?
What type of oil should be added to the transmission?
How do you add the oil?
These are pretty old models, and I have not done serious work on them recently so I am going to link you to a repair book that you will have to pay for, but not too much. It will help you with your current and future repairs, so well worth the investment.
Unfortunately GE does not have access to free tech bulletins/manuals for these machines.