How to install LineageOS (the successor of CyanogenMod) on OnePlusOne

Since CyanogenMod is not out there anymore I decided to move on to LineageOS - the successor of CyanogenMod. So now my OnePlusOne (aka OPO) is running the latest nightly version of LineageOS. If you ever flashed your phone chances are you'll be using a re-branded OS in no time. However keep in mind you do all modifications AT YOUR OWN RISK!

Flash the latest TWRP

• Download the latest TWRP for OnePlus One
• Attach your phone to your Linux computer
• Shut down your OPO
• Hold down Power + VolumeUp
• Now you are in Fastboot Mode
• As root type in the following commands:
• fastboot devices
• Check if your device is attached and ready
• fastboot oem unlock
• Unlock your device
• fastboot flash recovery twrp-x.x.x-x-bacon.img
• This flashes TWRP on your OPO

Flash LineageOS 14.1 and Gapps

• In your Linux computer:
• Download the latest version LineageOS for OPO
• I chose this one: lineage-14.1-20161230-UNOFFICIAL-bacon.zip 
• Download Gapps
• My options: ARM, 7.1 and Pico
• In your OPO:
• Hold down Power + VolumeDown to enter TWRP
• As soon as OnePlus One log appears release fingers
• Swipe to allow modifications
• Choose Swipe and after that Swipe to Factory Reset
• Go back
• Choose Advanced
• Choose ADB Sideload
• Check Wipe Dalvik Cache
• Check Wipe Cache
• Swipe to Start Sideload
• In your Linux computer:
• Type in the following commands as root:
• adb sideload lineage-14.1-20161230-UNOFFICIAL-bacon.zip 
• Wait until flashed
• In OPO: Choose ADB Sideload again
• In linux: adb sideload open_gapps-arm-7.1-pico-xxx.zip
• Thumbs up, wait and reboot

So, happy ending! One more thing: OnePlusOne supports MultiROM which I've been using before. It seems the latest nightly version of LineageOS doesn't like MultiROM just yet! Or I don't know how make them co-operate ;D.