Do what I resolved to do a couple of years ago - make your OWN rules as to how to play their 'game', and have resolute answers for anyone in a given circumstance!
Now the answer: I was handed a talk recently which seriously conflicted what I believe to be the truth. So after a few days, I went to the School Overseer with the slip and said, "I'm sorry Brother, but I've looked over this material and I cannot get my head around the subject material. Can you assign this talk to someone else, and give me another assignment?".
Be ready to firmly but meekly insist that you CANNOT deal with this assignment.
If he is so stupid to ask what it is that you can't understand, reply with a question - "Would it be too much of problem to give me another talk?".
If he still is obtuse, just say to his face, "I'm sorry, but I can't do this talk".
I'm very prepared (for a specific scenario) to look at our SO in the eye and say, "Please take me off the Ministry School". They do not want you to assert your God-given choice of free will. Tell him straight!
Any other questions from him, just tell him that you have private and personal issues to deal with, and that you don't want to discuss them with anyone at this time.
I've really screwed up my CoBE and Secretary's minds by refusing to discuss with them "my personal issues".
They cannot stand it when you refuse to give them info which brings you under their control; go ahead, do it - take control and let them know it!
Or simply just go and ask to be taken off the MS, temporarily, for personal reasons!
Best wishes for your courageous stand!