There are many ways to edit files, i will describe two different aproaches.
1) Editing files on the commandline:
2) Or you edit files with winSCP which might be easier for you, as winSCP is a windows GUI program.
You can login with WinSCP to your server remotely with user "root" and the password you chose during installation. WinSCP contains an editor to edit files like there where local on windows.