"Once I had to fire a lady I charge of the whole computer system but she was the only one who knew how to run it. She would never fully train anyone how to use it.
I decided to say we were creating a training manual and she was in charge of writing out the instructions for her and her assistant role. We also developed a training Manual for another department she sometimes helped in. We were able to finally fire her and actually developed the first trading manual for the company."
It would have been better story if she needed to retire for health but had a hard time training someone else in person, so she kept working. With a training manual she could finally retire.