Here is the first step:
http://steamcommunity.com/sharedfiles/filedetails/?id=893772412 In Cleve's own words here is his plan for GOG:
"The plan is to release it on Steam and let it percolate for a while. Tweak it in response to feedback and add improvements not present in it initially, like new graphics and gui widgets here and there.
Once it has seasoned like a fine wine and brought much happiness, a new release on GOG with all new map areas, enhanced gameplay and features as the "El Maximo Food Of Champions" Grimoire.
No matter what happens, only the IndieGoGo backers will get those particular limited editions sets physical media. No further printing of those materials will ever happen again once they are shipped out to backers."
I know several GOG higher ups have been waiting for this day but it doesn't hurt to remind them and also keep Cleve motivated on getting Grimoire GOG ready.