Almost forgot to post this here!
If you weren’t quick enough to get copies of Infernal Colopatiron while they were available, you can get copies of The Abyssal Angels, which is an affordable redux of Infernal Colopatiron (available in inexpensive hardcover, paperback, and ebook) that discusses gate opening and theophany and includes SOME of the information contained in Infernal Colopatiron. However, please note that Abyssal Angels IS NOT The Infernal Colopatiron.
The Abyssal Angels doesn’t go into the same depth as Infernal Colopatiron and does not include all of the material found in Infernal Colopatiron. Abyssal Angels can be bought in hardcover, paperback or ebook. (Nook, too.)
For those of you who own Infernal Colopatiron, there is nothing new in Abyssal Angels. This is, essentially, a stripped-down-for-mass-consumption version of the infamous grimoire.