I use vi a lot on nix machines and there’s a lot of useful tricks you can do to edit files.

A good trick to get rid of those annoying ^M characters from a dos file is –

:%s/(ctrl-v)(ctrl-m)//g

So you want to type :%s/  and then ctrl & v and without spaces ctrl & m//g

What you are doing here is just a regular expression, changing ^m for // (nothing – basically removing them from the entire file (g).