Before transferring ownership do your dad a favor and reinstall CM11 to the stock slot (overlaying FireOS). There are signficant problems with secondary slots in Safestrap v4:
- device never enters 'deep sleep' which severely impacts battery life
- only 2 of the 4 available processors are active - and both of those run at 100% at all times regardless of load
- WiFi connectivity is less reliable
- reduction in storage resources available for CM (not a big issue on larger devices or for 'lite' users)
If you opt for this path install a FRESH copy of CM11 in the stock slot, make sure everything is working and then delete slot 1. Do not attempt to backup slot 1 and then restore it to the stock slot; the device will brick. Also pay close attention to which slot is active when you are doing installs/deletes.
A small benefit of reinstalling CM: You won't have to purge personal data.
Final recommendation: leave a copy of the latest CM11 installation image on the device. It is the only way to recover if CM11 (or any OS) will not boot but you can still get to Safestrap recovery.
Sorry to complicate your day - but I would be remiss is not pointing out some of the problems with your current config.