Mount disk: sudo mount /dev/sda1 /mnt

Setup samba, bottom of file: cp smb.conf /etc/samba/smb.conf sudo systemctl restart smbd

Optional: sudo smbpasswd -a pi sudo systemctl restart smbd

External storage mounted in /etc/fstab, copy of file in repo. Note: permissions need to be set during mounting, otherwise changing file permissions may be denied, so fstab is needed.