Have tried several ways without success. Have installed and partly configured XML sitemap but Google Webmaster tools 100% refuses to accept the site map giving the following error:
Issue: Site is HTML
Description: Your Sitemap appears to be an HTML page. Please use a supported sitemap format instead.
Line: 3
I have tried turning off and on the option "Include a stylesheet in the sitemaps for humans.", but that's not worked.
Not sure if I'm doing anything wrong or if this is a bug so I'm submitting as a support request.
This is the best description I can give.