: If your manufacturer never released an official 5.0 update, you can "flash" a custom version of Android (like LineageOS ). This requires rooting your device , unlocking the bootloader, and using a custom recovery tool like TWRP . Risks of Patched or Unofficial Downloads Check and update your Android version - Google Help

If an update is available, follow the on-screen prompts to download and install. 2. Manual and "Patched" Update Options

: For some devices like the Nexus 5, users have had success by going to Settings > Apps > All > Google Services Framework , selecting Force stop and Clear data , then checking for updates again.

Before looking for manual downloads, check if your device has an official over-the-air (OTA) update available.

While successfully updating to Android 5.0 allows you to experience the birth of Material Design, it is functionally a "zombie" OS.