The POC will get any emails/messages from the issuer of the RFP. So if you'd like to change the POC, you can do that through the Details page.
The Details page is accessed from the RFP Dashboard:
Next within the Details page, click on the Point of Contact dropdown menu and choose any one of your users. After being selected click the Update Proposal button.
From within that page, click the Details tab.
Next within the Details page, click on the Point of Contact dropdown menu and choose any one of your users. After being selected click the Update Proposal button.