You can submit your sitemap to Yahoo or Bing by going to the Bing Webmaster Tools website. Please note that Bing and Yahoo have collaborated on a way for your sitemap to submit to both of them.
Here are the steps:
Go to http://www.bing.com/toolbox/webmaster and click on 'Sign In' if you already have a Microsoft Account, otherwise click on 'Sign Up with Microsoft Account.'
On the 'Add a Site' field, type in the web address of your website then click on 'Add.'
On the 'Add a sitemap' field, type in "http://www.yoursite.com/google_site_maps.htm" where "yoursite" stands for your domain name. This is assuming that you have already set up your Google Sitemap. If you haven't yet, please refer to support article Google Sitemaps.
Fill in the rest of the fields then click on 'Save.'
You will then be asked to verify your site ownership. Copy the tag on Option 2 and insert it on the tab of the Properties window of your Home page (i.e. click on 'Edit Page' -> 'Properties' tab). Please do not close the Bing Webmaster Tools page as you will go back here to verify your site.
Once you have inserted the meta tag on your Home page, go back to the Bing Webmaster Tools page then click on 'Verify.'
Your website should now have been submitted to Yahoo and Bing. Please be advised that it will take some time before the Bing Webmaster Tools page can finish indexing your sitemap.