To uninstall JFBConnect, you'll need to uninstall:
Component:
* JFBConnect component
Modules:
* JFBC Social Share
* SC Social Find Us
* SC Social Stream
* SC Social Widget
Plugins:
* Any plugins in the socialprofiles group
* Any plugins in the opengraph group
You would also need to remove the database tables manually:
#__jfbconnect_**
#__opengraph_**
In the past, we used to uninstall everything, but that removed all configuration settings, user mappings, Open Graph settings and other features of JFBConnect. That was a huge problem as some people tend to uninstall before even upgrading.
I hope the above helps you clean things up.
Thanks,
Alex