Expanding and Collapsing Webparts in SP 2013

I've been looking up how to expand and collapse webparts in a page, but a lot of the content was written for 2007 and 2010 (reference this other post on the forums).

I've tried getting the code on this site to work in SPO 2013, but its not doing anything in the page:

http://moblog.bradleyit.com/2009/08/sharepoint-expand-or-collapse-web-parts.html

I'm just curious if these instructions are still valid in 2013 or if I need to do something different now to get this to work.