Add ajax feature to an exisiting rating system in ruby on rails

Question

Hi I'd like to implement a simple rating system in rails 400 called lets-rate heres link https://www.ruby-toolbox.com/categories/rails_ratings#letsrate . The problem is that it is not ajax? Any tips on how to make it ajax greatly appreciated. Heres demo app : http://letsrate.herokuapp.com/ I looked into ajaxful rating but doesnt support rails 4. Thanks!