Refreshing Librem 5 sets the phone to factory defaults.
Attention , this procedure will completely erase everything from the device! Make a backup in advance!
Librem 5 gets reflashed from a separate 64-bit x86 computer running PureOS (or PureOS live).
Reflashing from that computer is as simple as installing the necessary packages:
sudo apt install git python3-jenkins python3-tqdm uuu
Downloading scripts and installing:
git clone https://source.puri.sm/Librem5/librem5-devkit-tools.git
cd librem5-devkit-tools sudo ./scripts/librem5-flash-image
The above procedure is demonstrated in this video: