FM 24 - how to change rules in editor?

Hi, could anyone tell me how can i change substitutions rules in any league (in free pre-game editor)? For example i would like in premier league to have 12 or 15 players on the bench not only 9 which is now. 

no longer current. I know how to do it. 

Can you tell me how you did it? Every time I try, it's giving an error.