I am trying to change the format to a reference and from (X, 2009) do it as X (2009). I right click on it but the edit option is not on. What can I do?
I tried it with other references and worked fine, it doesn't seem to want this changed...

I wasn't aware you could do this, I though you just had to 'exclude author' and then manually type in their name :$

How do you normally do it??

You right click on the reference, you chose the option edit and then you just type the author as you want it.
But ENDNOTE doesn't seem to want this particular reference changed......:-s

I must have a different version of endnote!

Me too, I can't do this in my version (XI).

Can you do it how I have to on endnote XI - which is to 'exclude author' and then manually type it in the text?

Alternatively - go back to your library and see what is different about this reference, or try inputting the whole entry again. It could be that you have settings for books set up differently to journals for example.