Change justification

Hi PCAPCA,
you can align the buttons to the right with a CSS rule similar to that:
body .really_simple_share div { float:right; }

You can center the buttons with CSS, them giving their surrounding div a fixed width, like this:
.really_simple_share { width: 300px; margin: 0 auto; }
Find the best width (approx 100px for every button) and put the code in your theme “style.css” file.