Not really needing further assistance, since i managed to finagle my way through it, but sharing this to hopefully help anyone else considering doing this.
Some of you may know how Samsung usually ignores their phones within months of release, so a suddenly new ota firmware years afterward for my phone (for sake of argument, an sm-n900) after I've long since moved on to custom ROMs was something i didn't expect. And given the notion of it possibly being for improving security, did warrant having to make time to break down for it.
Prerequisites:
Some of you may know how Samsung usually ignores their phones within months of release, so a suddenly new ota firmware years afterward for my phone (for sake of argument, an sm-n900) after I've long since moved on to custom ROMs was something i didn't expect. And given the notion of it possibly being for improving security, did warrant having to make time to break down for it.
Prerequisites:
- Install Samsung Kies 3
- Install Samsung phone drivers
- Download latest OTA from sammobile or any trusted mirror
- Download latest Odin
- Use TWRP to make a nandroid backup
- Download CF auto-root for your specific sub model
- If possible, have your phone charged. Even with my extended battery, the process burned 10~20% battery before all was said and done.
- Make nandroid backup to SD card from recovery.
- Boot into download mode (can toggle from twrp, or hold vol down + home + power button)
- Launch Odin. Connect phone in download mode to PC. Ensure only "auto reboot" and "f.reset time" options are enabled.
- Flash ota's .md5 image file (under AP selection). It will typically format it anyway, since Samsung's ota updates are an all or nothing kind of deal.
- Let the phone finish booting. This is important.
- Once booted on stock ROM, go to settings -> about phone. Tap build number a bunch of times to enable developer mode.
- Go to developer options -> enable usb debugging; if you have it (mine didn't), enable oem unlock
- Reboot phone to download mode
- Use Odin (again), select cf auto root file under AP. Flash. It will reboot a couple of times, going back to stock ROM once enabled.
- Once booted with root, download or sideload and install twrp apk. Launch; agree to terms and enable root permissions.
- Install twrp recovery for your specific model through app. Reboot to recovery mode (if all else fails, boot with holding volume up + home + power key).
- Wipe data (dalvik, cache, etc).
- Either restore nandroid with custom ROM install, or install a fresh custom ROM of your choice. Personally, i choose resurrection remix.
