I’m putting this here for my own future reference as much as anything else however if anyone ever bingles their way here it should be useful for them too.
I have a text file that has CRLF line terminators (which Windows uses to terminate lines) that I want to replace with LF line terminators (the UNIX way). Notepad++ demonstrates this rather well:

Notepad++’s Find/Replace feature handles this requirement quite nicely. Simply bring up the Replace dialog (CTRL+H), select Extended search mode (ALT+X), search for “\r\n” and replace with “\n”:

Hit Replace All (ALT+A)….and job’s a good’un:

Easy when you know how!!!
@jamiet
UPDATE, turns out there’s an even easier way. From Eugene in the comments below:
Another option is to go to Edit -> EOL Conversion -> Unix Format.