Sorry for the delay in getting back to this. We just had our big release of JFBConnect and still finalizing some bits from that.
There isn't really an easy way to replace the Kunena login area with a different module. The have a way to show other modules in that section, but it's very limited and seems squished to the right. To my knowledge, there isn't a way to just swap their login area with ours.
With that said, by modifying their template, it'd probably be pretty easily possible, but would take some work. If you're ok with the current login module and just wanted to add the social login buttons (Facebook, Google, LinkedIn), we have documentation for that already:
www.sourcecoast.com/jfbconnect/docs/thir...tegration-for-kunena
Right now, I'm not sure that replacing with the SCLogin module will do what you're looking for. You mention:
The reason I want to do this is because at a later stage I would also like to add the social login functionality. Also when someone clicks on 'Forgot your password? Forgot your username? Create an account' I would prefer this to appear in a pop up.
The social buttons can be added, as above. The Forgot xyz and Create account links wouldn't show unless you're using the modal view of SCLogin. In that case, the modal would show those links, but clicking them would go to a new page.. they wouldn't have their own popup, if that's what you're looking for.
I hope that helps explain, but if you have any other questions, just let me know.
Thanks,
Alex