How do I package many instructables into 1 book or package Answered

The sites owners do it by copying them into a PDF file, it's quite painstaking I believe.

You need to ask all of the authors permission too, before republishing their work (unless it's under a suitable licence)

You don't, the mods create those ebooks that you see on the front page, we can't do that, and we probably never will be able to.