Well before starting you should think of what you want - do you want a complete replica with all the pages appearing in the movie, or do you want a display-only piece? For the latter you would only need a book with roughly the same dimensions as the Necronomicon and just work on the covers so it looks like the book from the outside.
For a complete replica you should first of all get the pages. I haven't seen the remake yet and don't know how many pages are shown on screen, but I've seen a video on YouTube of a replica with a lot of pages; don't know if they are all screen accurate and don't know either if he got the pages from somewhere/someone or if he did them by himself. When you have the pages in the right dimensions, you could either get a hardcover book the pages would fit in, rip out the original pages and glue in the replicas, or build your own bookcover from plywood and glue your pages on.
You might also want to check out
this thread where the new Necronomicon was already discussed, and of course the search function will bring you to a lot of other threads about the old and new Necromomicon.
One last thing:
Are you asking for help, or do you want to offer your replica(s) for sale once you have finished it and want to check out already if there's a potential market? If so, you should ask in the Junkyard-section