How to set up modx to manage multiple domains correctly?

Hello all and thanks in advanced for the help!

I have a main domain with quite a few add on domains that are their own sites. Is it possible to set up one instance of Modx to manage all of them? Right now I have separate installs for all of them which is kinda a pain. I have searched high and low and I can't find anything shows a step by step on how to do it.

I would love if I could do this with any seo penalties.

Is this possible? If so, what is the best way to accomplish this?

Thanks

Lots of results here

I saw those, but almost all of those have you parking all your domains to point to your primary domain. This reflects negatively on rankings with google. I would like each domain to be it's own site in its own folder so the rankings with search engines do not get affected.

or at least that is my understanding on parked domains....if i am wrong, please let me know

I wrote a review/tutorial on how to do this with ContextRouter here, let me know if you have any questions.