Paste this into:
AuthType Basic AuthName "Private Dir" AuthUserFile /path/of/your/dir/.htpasswd require valid-user
Then we must create the password file /path/of/your/dir/.htpasswd.
We want to log in with the username "user", so we do this:
htpasswd -c /path/of/your/dir/.htpasswd user
Enter a password for "user", and you're done!