Changing excerpt length, Changing Add to cart button text and height of popup

Hello team,
Website link : https://elijah.ssquares.co.in/shop/

We need the following changes is the quick view popup
1) Increasing the excerpt length of product description to 500
2) Changing the “Add to Cart” button text to simply “Add”.
3) Please let us know how to decrease the height of popup.

https://awesomescreenshot.com/0b465lrtdd

We need support how to change the required things.

Thanks