Google Sitemap problem

Errors - Easiest Mehtod to create it again?

[contentmaster]

There has been a drop in my website's position and on checking the report, the message says that there are errors in accessing the sitemap. The xml file displays the following error message as well -
This XML file does not appear to have any style information associated with it.

I am not sure how to correct this problem.

1) Can I remove the old sitemap and try to generate a new sitemap and then submit it?
2) What is the easiest method that can be used to create it? The last time I tried, it created this sitemap with errors.

Any help will be highly appreciated