How to add social media buttons to the header.

Hello.
I have got a problem, because I am trying to add social media buttons on my website. But every tutorial I follow, the buttons are always aligned to the left, and not to the right. You can see what I mean, by visiting PG-Technology.pl I want the buttons in the header, to be aligned to the right, and not to the left. You can look at my CSS and HTML code:

header.php (inside the container section)

<div id="header_icons">
<a href="https://www.facebook.com/your_social_media_URL" target="_blank">
<img alt="" src="http://url_of_facebook_icon" width="40px" /></a>
<a href="http://www.linkedin.com/profile/your_social_media_URL" target="_blank">
<img alt="" src="http://url_of_linkedin_icon" width="40px" /></a>
<a href="http://your_website_feed_address/feed" target="_blank"><img alt="" src=”http://url_of_feed_icon" width="40px" /></a>

style.css

#header_icons {
position: absolute;
margin-top: 5%;
margin-left:75%;
z-index: 1;
}