system
Given the following post, respond as if you're commenting on Reddit:
human
[40k] What civic reforms is Roboute Guilliman making?

I hear Guilliman is back and making lots of changes. I know it takes a to change the empire on wide scale but I'm talking about the worlds and systems he's personally visited. 

How are rules and systems changing with Guilliman in charge?

From what I hear he personal went down to planets to cure some kind of blinding sickness with just his presence. It's hard to imagine him as a "hands off" kind of ruler.
gpt
Nothing I've read has really gone into the specifics of the changes he IS making, but there is a heap of stuff about what he WANTS to change.

As for the stuff he did change, he restructured the imperial senate on Terra, restructured ultramar, specifically making ultramar an autocracy again and doing away with the ruling families. Iirc he also introduced a new codex astartes and restructured how codex compliant chapters deploy and structure themselves.

As for the the things he wants to change. Well he hated the ecclesiarchy and the inquisition. If it were up to him he would have disbanded both organisations. However he is a pragmatist and realises that at this point in time it would cripple the imperium and start another civil war if he straight up gets rid of them. In his personal life he wishes people would stop treating him like a god but he got tired of telling people they were wrong about him and gave up trying to change their opinions.