I've been writing a short story a month for our post-NaNoWriMo writing group, Fictional Authors, and utterly neglecting the ending of my 2011 novel. I'm planning to re-read the story so far and my planning notes, and get the thing done by the end of July. That gives me two months to write the last chunk of story.
If I put a goal out there in public, it may help with getting it done. NaNoWriMo is all about the power of a monster deadline, and I've written eight NaNoWriMo novels so far, which is over 400,000 words. There are dictionaries that long. This will be book two of a trilogy and I'm already planning a different story for my novel this year, so book three will have to wait. I may have a better feel for it when I've finished book two.
My planning process for this book involved a lot of index cards in three colours, one for each plot thread. Those index cards got transcribed into Scrivener, and the novel was written in small chunks that could be easily moved around. I have the back third of the book partially done, so there's probably between 4k and 10k more to write, and then a whole other book to finish off the trilogy. And then I'll need to edit all three.
My novel this year will be a very different story, I already have the plot bunny for it, hatched after watching people so focussed on their phones they pay no attention to the rest of the world.