How to use Pinbin with WordPress Child Theme to overwrite original style.css?

great theme aigars !! thankyou.
im wondering how i can use a child css to override certain elements of the style.css sheet?, so that my customised css will not disappear when updating the theme
how do i do this?

This should get you started:

Further you can look into:

Basically you need to create a new theme folder with code>style.css inside it which is linked back to code>style.css for the original theme folder. From there you can write your own CSS inside your newly created style.css and it will overwrite the original one.