I spoke to someone with QB's help, we explored how to do it, the first time we did it, it messed up the customers, we had to use a backup to restore. We went into a sample company and tried again, it worked perfect. We went back into the company and tried again, it worked perfect, do a back up before you start the steps below :).

First: Single user Mode

Second: Hierarchal View

Third: Click on customer you want to become a job for another customer

Forth: Click on little diamond next to name, drag just a little to the right just a little, it will create a job for the main customer. In my case I have a resident that owns two properties, each had it's own ID #, I wanted one customer with a job attached, so I still had both ID #'s, but the were connected as a customer and a job. 

Worked like a charm, the second time we tried :).