PiMyLifweUp aricle here
The steps are basically:
1 Install Samba
sudo apt-get install samba samba-common-bin
2 Create a folder to share (do not use sudo)
mkdir /home/pi/shared
3 Share the folder by editing smb.conf file
sudo nano /etc/samba/smb.conf
[mysambashare]
path = /home/pi/shared
writeable=Yes
create mask=0777
directory mask=0777
public=no
4 Setup a user for the Samba Share
sudo smbpasswd -a mark
This creates a samba user called mark. You will be prompted to enter a password
5. Restart the samba service
sudo systemctl restart smbd