Replace add to cart button with email us button

I would like to replace the add to cart button with an email button but I'm not good in coding. Could someone just help me step by step ?

Click Email button it will open a form or?

And do this for all products or one product or some products?

You can follow this

and to remove add to cart, use this to Custom CSS

  div.sqs-add-to-cart-button-wrapper {
    display: none !important;
}