I am a newbie and clueless but what I share next is from my own personal experience.

I was in a similar situation as you. I called the number of the Function report cover sheet. I requested more time. She said, "How much more time do you need?" I stated a date about 5 or 6 more days down the road. She happily granted it and said she has notated in my file that I can have it in my such and such date . . . basically giving me about two weeks to fill out that monster.

How do you eat an elephant? A few bites a day. I guess that is a good way to deal with this Report. I did section E first. Then some of my other answer will say something about 'please see section E about . . . .'

Eat the frogs first. A Mark Twain expression meaning get the bad things out of the way first . . . then every thing else is easier. Tackle the tougher questions first . . . get them out of the way. I have heard others use this strategy. It seems to have worked well for me.