Adjust specific buttons in main menu.

Dear friends,

Can someone tell me who I can adjust the ‘social icons’ in my menu? (http://www.fransvandervleuten.nl). They must be aligned to the right. Is there a way to put them in one element or something?

I already used fire-bug but I have no idea where to start. Trying to affect them with Custom CSS didn’t work out either. I added them via ‘menu social icons’. If there’s a better way, that would be great.

P.s. I’m using the Twenty Twelve theme.

Thank you,

Frans