New book

I have decided that I will not read the new book in the series of Witch and Wizard, and that i would instead read something that I have read almost the whole series. This book is the last one of the Harry Potter series which I have been meaning to read so that I can finish the whole series. I haven't started reading the book quite yet but i will start soon. What I predict might happen in this book might be that Harry will most likely somehow defeat The dark lord (voldemort) by using the schools powers. By this I mean that he will take the whole school out to the battlefield to once an for all take down this evil that has tormented Harry and his school for now being 7 years. Some questions I have for this book are how is Harry going to defeat voldemort, if he does even battle him. Also I would really like to know what will happen to the school now that the headmaster has been murdered, will professor Snape or McGonagall take over the "thrown" per say of the school. What will happen to Fred and George Weasely (someone told me that something horrible would happen to them). But my one HUGE question would be what happens to Harry does he win or lose? Well I will just have to find out by reading the book. This is a trailer of the books movie. Part 1.   Part 2.