Removing the "hidden" class will do the trick.
Because bootstrap's hidden class has ! important, jQuery's .show() function won't perform correctly, just remove the class and the element will appear. This is tested with Bootstrap 3.3.4 and jQuery 1.11.2
To add a show effect, hide the element first before removing the hidden class, and then call whatever effect you want to use. For this example, I'd like to use a .fadeIn() effect, so here's what's I'm gonna code.