So some info: Phone - Samsung Galaxy On5 (T-Mobile) Computer OS: Arch Linux SuperSu file used - http://download.chainfire.eu/supersu-stable TWRP Image used - https://twrp.me/devices/samsunggalaxyon5tmobile.html Flashing Utility used - Heimdall So I downloaded both the SuperSu file and the TWRP Image. Stored the SS file on my sdcard. Enabled usb debugging. Used adb to reset my phone into Download Mode. Then used 'sudo heimdall -detect' to verify that it is visible. Then used 'sudo heimdall flash --RECOVERY twrp-3.0.2-0-on5ltetmo.img'. [quantum@quantum Downloads]$ sudo heimdall flash --RECOVERY twrp-3.0.2-0-on5ltetmo.img Heimdall v1.4.1 Copyright (c) 2010-2014 Benjamin Dobell, Glass Echidna http://www.glassechidna.com.au/ This software is provided free of charge. Copying and redistribution is encouraged. If you appreciate this software and you would like to support future development please consider donating: http://www.glassechidna.com.au/donate/ Initialising connection... Detecting device... Claiming interface... Setting up interface... Initialising protocol... Protocol initialisation successful. Beginning session... Some devices may take up to 2 minutes to respond. Please be patient! Session begun. Downloading device's PIT file... PIT file download successful. Uploading RECOVERY 100% RECOVERY upload successful Ending session... Rebooting device... Releasing device interface... [quantum@quantum Downloads]$ It seemed to work. I rebooted my phone and held the home button power button and volume up button to boot in recovery mode. First I get this 'Insalling system update...' For about 15 secs Next I get this screen 'No command...' For about 2 secs Then I get this screen I did both "Apply update from ADB" (by sideloading the ss file) and "Apply update from SD card" and I get the same message: Finding update package ... Opening update package ... Verifying update package ... E:failed to verify whole-file signature E:signature verification failed Finding update package ... Opening update package ... Verifying update package ... E:failed to verify whole-file signature E:signature verification failed Installation aborted. No idea what to do from here. Help please.