Ekk! Problem with !important declartions in plugin's CSS

So a plugin that I’m using as a lot of !important declarations in their CSS. Forcing me to also use !important declarations to override them. Annoying! But in some cases even using the !important doesn’t work.

I’m attempting to use my child themes CSS vs modifying the plugins CSSs because it will get overwritten if I update.

Here’s the page, It’s the tabbed widget all the way at the bottom.
http://trinidadpena.com/testing/carriepink/services/

This is the CSS that I can’t get to work.

.wordpress-post-tabs-skin-default .ui-tabs .ui-tabs-nav li a {
color: #FFFFFF !important;
padding: 4px 30px !important;
}

I’d like the default tabs to have more padding on the left and right and for text to be white.

Any suggestions to help override this? I’m tearing out my hair!