How to create a sitemap in a site with 2 wordpress

Hi,

I have 2 wordpress installations in my site.

One at https://www.stockmaniacs.net/site that points to main page of my site https://www.stockmaniacs.net/ and another one at https://www.stockmaniacs.net/blog/ pointing to the blog.

I use sitemap plugins for both the installations and I have 2 diffent sitemaps for them.

How can I specify 2 sitemaps in my robots.txt and also how can I upload 2 sitemaps in google webmaster tools.

Rgds

Indrajit Mukherjee