I can't play Wargroove anymore please help !

So I was playing wargroove on my mac and I went into option and video to change the size of the window. I miss clicked on the highest size of window possible and now the the window is so big that i can't reach the option to reduce it. I tried relaunch the game, reinstall it but every time it just come back with the same size of window. I can't even click on option. Please, please help me.
Here's a screen shot because its complicated to explain ( sorry for my english, i'm french).

 

First : Really thanks for your response but I'm sorry, I can be really be really bad on computer. Where do I look ? On my finder or on Steam ?