You will need to install a user script manager extension to install this script.
Made by Hayden Schiff (oxguy3), license is Creative Commons Zero.
This script makes it really easy to download a DRM-free copy of your digital comics on Dark Horse Digital. Simply go to your Dark Horse bookshelf, then disable "Stack by Series" and switch to Gallery View if you haven't already. You will now see a "Download" button below all your comics.
When you click the download button for any of your comics, it'll open the reader for that comic, then start downloading the comic. A red box in the middle of the screen will show you the progress of the download (be warned that things may be a bit laggy while it's downloading). Once it's done, a .CBZ file will pop into your downloads!
If you aren't familiar, a .CBZ file is just a zip file full of JPGs. You can easily open it with a reader app or convert it to a PDF or whatever.