Thanks for looking into it everbody.
"Keep a record of the old URLs and do an htaccess redirect from the old pages to the new ones.
Could you show me how to this (maybe a link)? Tried google, but no luck ?
He has alot of pages should i manually copy all pages, not quite sure how to do this ?
You could also add a canonical tag, just to make sure Google sees yourwebsite.com and www.yourwebsites.com and http://www.yourwebsite.com as one page.
Is this also important if i am not using a CMS ?