Just to put things into perspective,
if these URLs are all already indexed and you have used "noindex" on those pages, sooner or later google will re-crawl these pages and they will be removed. You may want to remove them from the index ASAP for some reason, but it wont really change anything. Because Google will not deindex your noindex pages just because they are in your sitemap.xml.
Google deindexes a sie only when it is time to re-crawl the page.
Google never recommends using noindex in sitemaps, and google wont suggest that in their blocking search indexing results guidelines. Also Google indicates the following:
"Google will completely drop the page from search results, even if other pages link to it. If the content is currently in our index, we will remove it after the next time we crawl it. (To expedite removal, use the Remove URLs tool in Google Webmaster Tools.)"
But hey! every SEO has its own take.. Some tend to try outsmart Google some not..
Good luck