I checked on SMF's forum first actually.

I cannot locate any instructions there, and I know they'll send me right back here if I open a thread there about JSMF.

Since this is a JSMF question, I think the question should be asked here.

Well, there is nothing really to convert, per se.  I have used both bridges at one point or the other.  Just need to make sure you go back to the JSMF component in Joomla backend admin and select the "Install" menu.  Then look at each of the options on that screen and make sure to "unpatch" each selection in the install screen.  Then things should be as they were prior to the bridge/patch.  You can then use the official bridge instructions at the SMF website to install from that point forward.  I would uninstall the JSMF component once you got things working the way you want. 

I will say that I had a heck of time with the Orstio bridge (earlier versions) and it whacked out my SMF forum inside the Joomla template.  So make sure you have backed up your SMF and Joomla folders on your website before you start messing around with their bridge. 

Of course, with the politics of Joomla/SMF at the moment, you will get no Orstio support since they are fighting over license  issues and the bridge has been taken down (hopefully only temporarily).

Cheers,
Chris 

Why using PHPbb? There core team from both party’s are talking about an solution. We all have to be patient.