Yes - thanks anyway, I read through the documentation. Which is basically saying, get your act together BEFORE you create your pages ... in a perfect world. Anyway, I've worked it out.
So for anyone else wanting to rename the /pages directory after the event (i.e. after the search engines have indexed your content), here is how I did it on my Linux server:
1. On the server I created a duplicate copy of the /pages directory, named say /newpages - just in case someone was trying to log to my site from search results while I was making the changes
2. In wb back-end settings, I clicked on advanced settings and changed the Pages Directory to /newpages
3. I then checked all my page links were working correctly with urls
http://www.domain.com/newpages/page.php etc.
3. I edited the .htaccess file using notepad and added the following line of code:
redirect 301 /pages
http://www.domain.com/newpages4. I then checked the redirect was working by following links to .../pages/... to make sure I ended up on .../newpages/...
5. I then safely deleted the /pages directory.
I am no expert on .htaccess or 301 redirects, so perhaps you should check that a 301 redirect is going to work on your server before you embark on this.