How do you delete packs without opening minecraft

Hello,

I am having a problem where I have downloaded a client on my Macbook, but I am unable to deactivate it. It is called "Astral Client". The problem occurs when I try to click play and settings.

Play:

It will not let me go to my worlds or do anything

Settings:

It will crash the game

I don't know how to fix it, I will really appreciate it if I could have some help with this, and I will not make the same mistake as I did before. 

Thank you!