I kinda doubt those of us who aren't programmers can. Sounds like he cracked open the game's code to do that.
Of course, like I said a couple pages ago, sure would be nice if a code-savvy person could create a mod to disable autosaves and share it with the rest of us...
Zipped and uploaded to nexusmods with instructions. Had to finish the game first
http://www.nexusmods.com/pillarsofeternity/mods/14/?
This isn't compatible with IE Mod, since it includes a modified version of the same game file. It'd be pretty easy for its author to add this in there though.