Samba file sharing with external access

[Linux for blind general discussion]

Hi,

I use Samba for sharing content of my external 6 Tb hdd for my local 
network. Now, I want to redirect my hdd to all members of my family, but 
it requires public access. I have public ip address. So how is the best 
way to configure Samba for access with my public ip? I have all users 
and passwords created and I will use Ubuntu and I'll try to use 
gadmin-samba package, but I have no experience with this type of 
sharing, so if you have some tips, you can give them.

Thanks,

Pavel