patricksharma on "Don't know how to change domain name DNS settings"

I'm completely confused about how to move my WordPress site (www.patricksharma.wordpress.com) to http://www.patricksharma.com, which I bought through Google. I recently purchased domain mapping from you guys, but do not know how to change the domain name DNS settings to NS1-NS3 WordPress.com. Is this something that you can help me with? Thanks.
Blog url: http://patricksharma.wordpress.com/