Code
systemctl stop kodi.service
mv /storage/.kodi /storage/.kodi-old
tar -xvf backup.tar
systemctl start kodi.service
^ something like that will move the existing Kodi folders out of the way then unpack the backup to recreate folders and test by restarting Kodi. To make and restore backups and test them you'll need 2x-3x the size of the backup as free space on /storage