All you need to do is to to use...
data-toggle="collapse"
data-target="#ElementToExpandOnClick"
...on the element you want to click to trigger the collapse/expand effect.
The element with data-toggle="collapse" will be the element to trigger the effect.
The data-target attribute indicates the element that will expand when the effect is triggered.
Optionally you can set the data-parent if you want to create an accordion effect instead of independent collapsible, e.g.:
I would also add the following CSS to the elements with data-toggle="collapse" if they aren't <a> tags, e.g.:
.panel-heading {
cursor: pointer;
}
Here's a jsfiddle with the modified html from the Bootstrap 3 documentation.