Because bridge 1.1.7 changes NOTHING in SMF and Joomla, all you need to do is uninstall the bridge component, the bridge registration component, the bridge login module, and the SMF_header_include mambot.
After uninstalling those four things, you no longer have a bridge between Joomla and SMF. It does not change either software in any way, so you will be left exactly where you started before installing the bridge.