X-acto knife or Dremel
2) Mark where you will cut. I did 3/4" from the edges.
3) Use the knife to cut the pages out. Leave a couple pages uncut at the back. This took me a couple hours and my hand was tired but it wasn't too difficult. I wish I had a dremel with a blade for this part.
4) Put another layer of thick mod podge over the inside edges of the paper.
5) Place plastic wrap between the cover and the pages then put something heavy on top and let it dry. This takes a while. Now just hide things in it!
I found my book a the dollar store. It wasn't as thick as I originally wanted but it was the thickest one they had and I think the title is fitting.