[Samba] samba outside of LAN

[OrzzrO]

Hi, All

           I have set up a samba enviroment on a ubuntu server. I can see it
using  "smbclient -L localhost".  But now I want to access the samba server
using a Windows PC, and they are not in LAN. I cannot access the server
using \\server_ip <file://server_ip/>.  Someone suggested using SSH, but I
don't know what to do in detail.   Any help will be gratefully received.
Thanks.