I don't know if you can run the Piked installer from the recovery drive ... I don't think you can. So, you'll have to boot from an old drive, mine was 10.7.5 with all other drives removed since I have no boot screen, mount the drive via usb or select the working drive as the startup, shutdown and reinstall the drives, then select the drive you want to install to and allow the piked installer to do it's thing. I've done it several times and all accounts and apps were in tact after installation. Good luck. Beware of things like Tinkertool and things like that, that may alter the system files. If that doesn't work, boot from recovery, completely restore the drive from your backup ... it most likely won't be a working system at that point so you'll still need to run the Piked installer after you restore from BU. Good luck.