Transfer wordpress.com blog to own domain and keep traffic?

I started my IM career 4 years ago by throwing up a free wordpress blog site and writing aimless articles about some areas of expertise, but was abandoned a few months later when i realized i could not place adsense ads on the free wordpress site.

So i created my domain, and started fresh. The new domain wordpress made 3-4 $100 min adsense checks but I was so busy with new business going, i forgot to renew the domain name and lost it, but recently got it back.

Because this 2nd domain blog wasn't up for long, but did make money it's no where to be found on the search engines anymore.

My question is related to the first free wordpress blog I created. I somehow remembered the password the other day and when i logged in the thing had like 130K page views over 2-3 years on just a handful of articles.

The traffic has really grind to a halt last year.

Is there a solid way to take the free wordpress blog and somehow register it on a new domain name where I can monetize it without losing all the rank that I have with the free wordpress blog? Some type of plugin or tool?

It would be nice to re-energize this site with some fresh content and learned SEO tactics (the basics) and see if I can get traffic back going and maybe make a few bucks with minimal effort.

Sorry so long in advance!