Padding modify

Hi,
I’ve to modify a padding value in this file https://my_site/wp-content/plugins/footer-putter/styles/footer-credits.css?ver=1.14.1 at this line:#footer .footer-center, #footer .return-center, .footer-center, .return-center { text-align: center; padding: 10px 0px; border:none;} (the first line)
I want to modify it by custom css section in my theme. How can do it?