how to modify /etc/ftpusers

Dear All,

 will any one know how to edit /etc/ftpusers file and comment some lines
and how to save?

The best and easiest-to-use tool for editing in the console, so I think, is
the mcedit program that comes with the midnight commander (also this is a
great tool for file management).

Or you can use Vi - which is installed by default.