Forgive me if this is posted in the wrong section but this was the only one that made sense to me:

I was messing around with something and renamed "/usr/libexec/securityd" to "/usr/libexec/securityd.bak" not realizing how badly this would screw things up. Now my phone won't boot past the Apple logo and I need to copy or rename that file back to it's original name.

I can tether my phone, put it in recovery mode, and get to it through iRecovery but I don't know what command to use to name the file back. Perhaps I am not understanding how the recovery shell works but this is what I tried to no avail:

Code:
fs mv /usr/libexec/securityd.bak /usr/libexec/securityd
Is there something else I have to do first like mount the file-system? Any help would be greatly appreciated as I lost the only backup I had of my phone so I don't want to restore it.

Thanks!