Para desinstalar o Tails de uma memória USB e usá-los para alguma otura coisa, você deve resetá-la.

The content of the USB stick will be lost in the operation, but an attacker might still be able to tell that Tails was installed on that USB stick using data recovery techniques unless you securely clean all the available disk space afterwards.

Using GNOME Disks

Você pode sobrescrever qualquer disco rígido no seu computador. Se em algum ponto você não tiver certeza de qual dispositivo escolher, interrompa o procedimento.
  1. Tenha certeza de que a memória USB que você quer resetar esteja desconectado.

  2. Choose Applications ▸ Utilities ▸ Disks to start GNOME Disks.

    A list of all the storage devices on the computer appears in the left pane of the window.

  3. Conecte o pen drive que você quer resetar.

    A new device appears in the list of storage devices. This new device corresponds to the USB stick that you plugged in. Click on it.

  4. In the right pane of the window, verify that the device corresponds to the USB stick that you want to reset, its brand, its size, etc.

  5. To reset the USB stick, click on the Menu button in the titlebar and choose Format Disk….

  6. In the Format Disk dialog:

    1. If you want to erase all data securely, choose to Overwrite existing data with zeroes in the Erase drop-down list.

    2. Choose Compatible with all systems and devices (MBR/DOS) in the Partitioning drop-down list.

    3. Click on the Format… button.

  7. Na caixa de diálogo de confirmaao, clique no botão Formatar para confirmar.

  8. To make sure that all the changes are written to the USB stick, click on the Eject button in the titlebar.

Resetting a Tails USB stick from itself

If Tails is your only Linux system, you can generally reset a Tails USB stick directly from that USB stick while running Tails.

  1. When starting Tails, add the toram boot option in the Boot Loader. For detailed instructions, see the documentation on using the Boot Loader.

  2. If Tails starts as usual, follow the instructions for resetting a USB stick using GNOME Disks.

    If the system fails to start, that means that the computer does not have enough memory for this operation mode. Try with another computer, or find another Linux system, such as another Tails USB stick, to do the reset from.