How to delete cookies for a specific site

1. Click the document icon next to the URL.
2. Click the "... from this site" link under the Cookies section.
3. Highlight the cookie and choose Remove. You can also Block the whole site.

You can do it through Chrome settings. Just go to Preferences -> Options -> Under the Hood -> Content settings -> All cookies and site data...

There you can filter single domain from the list and delete the ones you like.

The bookmarklet from http://ostermiller.org/bookmarklets/cookies.html should work without modification. Just visit the target website first

javascript:void((function(){var%20a,b,c,e,f;f=0;a=document.cookie.split(";%20");for(e=0;e<a.length&&a[e];e++){f++;for(b="."+location.host;b;b=b.replace(/^(?:%5C.|[^%5C.]+)/,"")){for(c=location.pathname;c;c=c.replace(/.$/,"")){document.cookie=(a[e]+";%20domain="+b+";%20path="+c+";%20expires="+new%20Date((new%20Date()).getTime()-1e11).toGMTString());}}}alert("Expired%20"+f+"%20cookies");})())

In Chrome 60+ it's now in the dev tools (F12) - Application tab - Clear Site Data