alekv on "Eliminate external render-blocking Javascript and CSS in above-the-fold content"

Hi

When testing the performance of my site with http://developers.google.com/speed/pagespeed/insights/ I get a strong recomomdation to "Eliminate external render-blocking Javascript and CSS in above-the-fold content".

How can I achieve this with wordpress without using plugins? If there is no other way than using a plugin, which one is the best (or most standard) one?

Thanks
Alekv