The Heroes Round Table

I recently got into HoMM 5 mod making (for my single player) and I want to change the requirements for those ultimate hero skills like Howl of Terror and Urgash’s Call. I greatly reduced what prerequisite skills are needed to be able to choose those ultimate skills and that works fine, but now I ran...

I would like to play around and edit my save game files, but they are not read-able by a simple program like Notepad.

Is there a save game editor (or converter) that works for Heroes of Might & Magic 5?