1. Type `adb devices` on your terminal (for Windows users: open the terminal in the directory containing adb&fastboot.exe and use the `.\` prefix. The resulting command will be: `.\adb devices`).
1. If your Fairphone reboots, you might have to do the steps 2.1-2.4 again to re-enable USB debugging. Then `adb reboot bootloader` will bring you back.
1. On the terminal type `fastboot flashing unlock`.
2. Install fastboot image & reboot to recovery by typing on the terminal `fastboot flash recovery <image_filename.img>` (<image_filename.img> is the img-file you have downloaded in 1.).
3. Reboot to recovery without starting your original rom: With the device powered off, hold Power + Volume Up. Release when boot logo appears.
3. For Fairphone3
1. On the terminal type `fastboot flashing unlock`.
2. Install fastboot image & reboot to recovery by typing on the terminal `fastboot flash recovery <image_filename.img>` (<image_filename.img> is the img-file you have downloaded in 1.).
- If you see something like "boot partition is smaller than boot image" you might find the solution [here](https://gitlab.com/domaindrivenarchitecture/lineageos-Fairphone/-/blob/main/Guides/InstallationFAQ.md).
3. On the phone you should not see any difference and it should remain in the bootloader screen. Then hold Volume Up + Power. Release when boot logo appears.
4. Reboot to Recovery without starting your original rom:
2. Or use the button method, hold Volume Up + Power. Release when boot logo appears.
4. For Fairphone4
1. On the terminal type `fastboot flashing unlock`.
2. Do the steps 2.1-2.4 again to re-enable USB debugging. Then `adb reboot bootloader`
3. On the terminal type `fastboot flashing unlock_critical`
4. Do the steps 2.1-2.4 again to re-enable USB debugging. Then `adb reboot bootloader`
5. Install fastboot image & reboot to recovery by typing on the terminal `fastboot flash recovery <image_filename.img>` (<image_filename.img> is the img-file you have downloaded in 1.).
Please take care not to boot your old Android / FairphoneOS. If you missed the proper reboot to recovery by buttons you are back to step 1. because your old os reinstalls its own recovery over the one just installed.
If you really need the google Apps or the google Play Store there are packages with various scopes, you will find a package comparison here: [https://github.com/opengapps/opengapps/wiki/Package-Comparison](https://github.com/opengapps/opengapps/wiki/Package-Comparison). You have to install google Apps before the first start.