The book goes from telling you how to do a hand stand against the wall, how to gradually rely on the wall less, how to do it without the wall, how to walk on your hands and how to do a freestanding pushup.
I am sure it will take at least 1-3 months to be able to do it well, but the instructions are clear and plentiful.
I look forward to trying it. I think pull ups and handstand pushups are two of the best exercises you can do, and you don't really need any equipment at all for a handstand push up.
Lets hope I manage to do it!