Here are the steps to update the provider PIN.
Go to the Setup Tab
Click on Providers
Select the provider from the dropdown box that you need to update this info for
Click the Edit Provider Info button
Scroll down to the page, just under the "Save Provider Info" buttin
You can locate the "insurance plan" and Provider PIN already entered
Click the blue Edit link to the left of that line
Make the changes and then click the blue Update link on the left
To see these changes in the billing app, please close and launch Billing Manager again.