i have a gaming site, and i submitted sitemap.xml to google webmaster last month now i want to submit again to update new links, should i remove existing sitemap.xml
overwrite it and resubmit in webmasters tools so it should remove dead links if you have and update fresh ones
Just upload it, you don't even have to resubmit it. I'm doing it in this way and the webmaster tools get upgraded themselves with the new sitemap after few hours or a day.