Modify records from multiple forms

Hello,

I have been trying to figure out how to share information across several forms. For example, I have a main form that is used to capture customer information (named Customer) and another that is used to generate an estimate (named Estimate). I am using the lookup tool on my estimate form to reference the customer form and to bring in customer information (named Customer) but I have not figured out how to get the estimate form to publish information to the customer form.

This needs to allow me to publish content from the estimate form to existing entries in the customer form without creating a duplicate. I have looked into the fetch and modify functionality and I believe that this is the way to go, but I cannot seem to get it working right or understand it completely.

Thank you for your time and help, it is much appreciated.