How to download Galaxy S4 in safe mode?
Restart or just turn on the phone.
Wait until your phone's screen an animated logo of Samsung.
Once the animated logo will appear Samsung - press several times on selection key options (this is the left softkey telephone).
Thus, the phone switches to the safe mode and it displayed evidence of this inscription - Safe Mode.
To exit safe mode, ie, enable normal phone, just restart your phone:
Turn off your phone -> Remove and replace the battery -> Turn on the phone.