DEF filler cap stuck? won't budge

[eternam]

Hey everyone, first time BMW 2012 X5 x35d owner and Xoutpost poster. I have a dumb issue. I got the no start in 1000 miles DEF warning. I've read how to fill both the active and passive tanks.

I can't for the life of me get the filler cap off of the active tank. Others say you can just twist if off with your hand. Is it just on too tight? Are there release clips or do I need to push and pull a certain way like a prescription bottle?

I also used the red tool with the square end and it just snapped the plastic square off the filler cap.

I did numerous searches and I seem to the only moron who doesn't know how to take the cap off. I have not tried to take the passive tank filler cap off.

Thanks in advance!