Connect using putty (http://the.earth.li/~sgtatham/putty/.../x86/putty.exe) and login with your username and password.
Browse to the directory where the file is located and delete the file using the command 'rm'
This is really basic stuff. Have a look here: http://www.ee.surrey.ac.uk/Teaching/Unix/unix1.htmlCode:~# cd /etc /etc#rm smb.conf