Notes about installing Lineage OS on Nexus 6P

Checklist for myself for the next time I’ll be flashing my Nexus 6P (because official Lineage OS instructions are missing some important parts).

• Install latest TWRP (from within itself if present, using fastboot otherwise)
• Download proper version (look on XDA) of factory image. We’ll need vendor, radio and bootloader images from there
• Download and put on the device
  • Lineage OS .zip
  • gapps for arm64 .zip
  • some su .zip
• Reboot into the bootloader (Power + VolumeDown), attach USB cable and use fastboot to flash vendor, radio, bootloader. And maybe TWRP, if not already latest. You need to reboot bootloader between each step. Running fastboot can require sudo. Exact commands can be found in shell files inside a factory image. Pay attention to a fastboot version check here (if present)
• Follow official instructions from that point
  • Wipe System, Cache, Data
  • Queue 3 .zips
  • Flash