The handover was very quick and I recreated most things from scratch except for the file with the WireGuard keys which I transferred to the new server via FileZilla.
I archived and zipped the entire WireGuard configuration folder with the tar command and then transferred it with FileZilla, an SFTP software, to the Raspberry.
sudo tar -czvf wg_config_backup.tar.gz /etc/wireguard
-c Create - creates a new archive.
-z Gzip - compresses the archive with gzip. This makes the file smaller and gives it a .gz extension.
-v Verbose - shows the list of files being added to the archive.
-f File - specifies the output file name (must be the last option).Subsequently I completed the configurations and verified with some tests that everything was working.