/etc/samba/smb.conf

smbpasswd -a username 

Will create smbpasswd wherever it's configured on that machine.

Nuke: smbpasswd -x username

---
smb.conf

[share]
   comment = Share
   public = no
    browseable = yes
    valid users = username1 username2
    read only = no
   path = /share
    force create mode = 0775
    preserve case = yes
    writable = yes