Thanks for the help. I was able to login via putty and get the screen with the freq values. However, not sure where on the screen to type the "i" and "!wq" commands.
Just press "i" on the keyboard when the file is opened.
The other one was a typo. After editing you need to press ESC button and type the below code and press ENTER to save the edited file.
Upon window close PUTTY will auto close the connection. Or may manually exit as said in the earlier post.
CODE:
:wq