Optimization - Removing unsed assets (CSS & JavaScript)

Hello guys! First of all let me thank you for making a pretty good work with this theme, is very nice :-)

I have a question about it:

How can I detect and remove all unnecesary assets, speacially css and javascript (most important), in order to optimize the site and save resource, I’m from Venezuela and here we have the worst Internet connection of the entire World, sad but true.

Examples: I will not use: Twitter Feed Fetcher, Instafeed, Jribbble, jquery.mb.YTPlayer, easy-pie-chart and many other than even I don't know what they do. I'm afraid to broke some dependancy and mess up the site :-/

I will await your answer, thank you so much and please forgive my bad English :-(

All the best.