Install TWRP, LineageOS, and Root on a Samsung Galaxy S7

I wrote this guide after combining the official LineageOS instructions with a modified recovery-flashing sequence that worked on my Galaxy S7.

Supported variants

TWRP recovery TAR for herolte or hero2lte, as appropriate for the exact device
Odin 3.12.3 with the Galaxy S7 fix
LineageOS for herolte or hero2lte
LineageOS Superuser package
OpenGApps for ARM64 if Google applications are wanted; the original installation used the Nano package

Open Settings > About device > Software info, then tap Build number seven times.
Return to Settings > Developer options and enable OEM unlocking.
Power off the phone, then hold Volume Down + Home + Power to enter Download Mode. Press Volume Up to continue past the device warning.
Connect the phone to the Windows PC.
Open Odin, select Options, and disable Auto Reboot.
Select AP, choose the downloaded TWRP .tar file, and start the flash.
After Odin finishes, hold Volume Down + Power until the charging-battery screen appears.
Disconnect the USB cable, then hold Volume Up + Home + Power until the Galaxy S7 logo appears to boot directly into recovery. This immediate recovery boot is important; otherwise the stock system may overwrite TWRP and require repeating the Odin step.
In TWRP, open Wipe > Format Data, enter yes, then use Advanced Wipe for the partitions required by the installation.
Copy the LineageOS, Superuser, and optional OpenGApps ZIP files to the phone. You can use Windows Explorer, a Micro-USB OTG drive, or ADB:
```
adb push filename.zip /sdcard/
```
In TWRP, install LineageOS first, followed by Superuser and OpenGApps if those packages are wanted.
Reboot into the newly installed operating system.

LineageOS 14.1 installation guide for herolte — Heimdall returned Failed to access device. libusb error: -12 in the original setup.
Video referenced during the original installation — it omitted several steps included above.