Help switching from WordPress hosted to my own hosted blog (redirect URLs)

So I’ve had a blog hosted on wordpress.com. I now want to have it hosted on my domain (and a new url structure). I have wordpress installed on my domain and it’s up and running. Problem is – I want to redirect all of the old URLs to the new one.

The old URL structure is: blog.domain.com

The new URL structure is: domain.com/blog

How do I go about redirected the wordpress-hosted blog URLs to the new ones? Thanks for the help – I appreciate it