Welcome to the Q&A Forum

It really depends on the extent of the damage whether you need a pro or not.  If it's all self contained, as it sounds like, then it will just take identifying the duplicates, and fixing the linking problems. To find duplicate articles just copy a part of the content and Google it with quotes around it.  This will search for that exact text, and allow you to find the instances that it shows up on your websites.  Fix accordingly. As for the links, it's pretty much just a matter of using some link searching tools, Open Site Explorer and Majestic SEO, and finding all the instances where you have outbound links from one site to another.  For the time being I would just separate them completely.  After they recover you can go back to connecting them. I just did this for a company out of Florida.  They created their own link network, and it ended up penalizing them.  They recovered in 3 weeks.  They had a penalty, lower case and less destructive, and not a Penguin or Panda.