One thing I did at a large organisation that was resistant to embracing user research was post a highlight reel video of users struggling with basic functionality of the website (I had to get permission from the participants for their session to be used in this way, obviously). It ruffled some feathers and got a lot of people defensive, but it also opened up a conversation that got people thinking about this stuff and brought potential allies out of the woodwork.
You do need to preface something like that with wording that makes it clear you’re not pointing the finger at anyone, and be transparent about your reasoning for why you are showing them this (UX is everyone’s job, and I want everyone to care about this stuff as we all impact it, etc etc).
Another idea would be to run some “brown bag” lunchtime education sessions, where you get folks playing design games like those found in the excellent book “Gamestorming”. These can be really fun with the added bonus of building relationships and getting folks thinking about putting the user first.
Let us know how you go!