Change store legal entity to dedicated LLC

[Seller_]

Is there anyone here who has the answer to "Changing the Legal entity for your store"? 

We started as a DBA on our other company and uploaded the legal documents at Shopify. Everything went well and we are almost ready with the store but not launched as yet. However, we decided to move ahead with our store's designated LLC instead of piggybacking as DBA. Now we have a new EIN for the dedicated LLC for the store but I don't know how to update this information with Shopify. I have been on forums and support chats since morning. The" request a call back" feature suddenly disappeared from my support options. Can someone help? Thanks?