Search & replace in Database

Hi!

I need to remove a subfolder in the “guid” field in my database:

The old domain is: “http://www.nanmelville.com/nm”
and what I need is: “”http://www.nanmelville.com”.

Using this article in the Codex:
http://codex.ww.wp.xz.cn/Changing_The_Site_URL#Domain_Name_Change, I entered the following:

UPDATE wp_nm_posts SET guid = REPLACE (
guid,
'http://www.nanmelville.com/nm/',
'http://www.nanmelville.com/’);

but am getting an error code from phpMyAdmin:

#1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ''http://www.nanmelville.com/’)' at line 4

What am I doing wrong?

Thanks
peter