Add instructions to modify data network following engineering review

Author: b-branco

articles/private-5g-core/media/modify-packet-core/modify-packet-core-attach-data-network.png

@@ -21,15 +21,15 @@ Each Azure Private 5G Core Preview site contains a packet core instance, which i
     > [!NOTE]
     > You can't update a packet core instance's **Technology type** or **Version** field.
     >
-    > - To change the technology type, [recreate the site](create-a-site.md).
+    > - To change the technology type, you'll need to delete the site and [recreate it](create-a-site.md). <!-- TODO: link to new site deletion section -->
     > - To change the version, [upgrade the packet core instance](upgrade-packet-core-azure-portal.md).
 
 - If you want to make changes to the attached data network, refer to [Collect data network values](collect-required-information-for-a-site.md#collect-data-network-values) to collect the new values and make sure they're in the correct format.
 - Ensure you can sign in to the Azure portal using an account with access to the active subscription you used to create your private mobile network. This account must have the built-in Contributor or Owner role at the subscription scope.
 
 ## Modify the packet core instance
 
-To modify the packet core and/or access network configuration:
+In this step, you'll navigate to the **Packet Core Control Plane** resource representing your packet core instance and start modifying it.
 
 1. Sign in to the [Azure portal](https://portal.azure.com/).
 2. Search for and select the **Mobile Network** resource representing the private mobile network.
@@ -46,21 +46,47 @@ To modify the packet core and/or access network configuration:
 
     :::image type="content" source="media/modify-packet-core/modify-packet-core-configuration.png" alt-text="Screenshot of the Azure portal showing the Modify packet core option.":::
 
-7. In the **Configuration** tab, fill out the fields with any new values.
+7. If you want to make changes to the packet core configuration or access network values, go to [Modify the packet core configuration](#modify-the-packet-core-configuration). If you only want to make changes to the attached data network, go to [Modify attached data network](#modify-attached-data-network).
+
+### Modify the packet core configuration
+
+To modify the packet core and/or access network configuration:
+
+1. In the **Configuration** tab, fill out the fields with any new values.
 
-   - Use the information you collected in [Collect packet core configuration values](collect-required-information-for-a-site.md#collect-packet-core-configuration-values) for the **Custom ARC location** configuration value.
+   - Use the information you collected in [Collect packet core configuration values](collect-required-information-for-a-site.md#collect-packet-core-configuration-values) for the top-level configuration values.
    - Use the information you collected in [Collect access network values](collect-required-information-for-a-site.md#collect-access-network-values) for the configuration values under **Access network**.
 
     :::image type="content" source="media/modify-packet-core/modify-packet-core-configuration-tab.png" alt-text="Screenshot of the Azure portal showing the Modify packet core Configuration tab.":::
 
+2. If you also want to make changes to the attached data network, select the **Data network** tab and go to [Modify attached data network](#modify-attached-data-network). Otherwise, go to [Submit and verify changes](#submit-and-verify-changes).
+
+### Modify attached data network
+
+To make changes to the data network attached to your packet core instance:
+
+1. In the the **Data network** tab, select the data network.
+
+    :::image type="content" source="media/modify-packet-core/modify-packet-core-data-network-tab.png" alt-text="Screenshot of the Azure portal showing the Modify packet core Data network tab.":::
+
+2. Use the information you collected in [Collect data network values](collect-required-information-for-a-site.md#collect-data-network-values) to fill out the fields in the **Modify a data network** window.
+
+    :::image type="content" source="media/modify-packet-core/modify-packet-core-modify-data-network.png" alt-text="Screenshot of the Azure portal showing the Attach data network screen.":::
+       <!-- TODO: Update screenshot after release of Simpler ASE Install feature -->
+
+3. Select **Modify**. You should see your changes under the **Data network** tab.
+
 ### Submit and verify changes
 
 1. Select **Modify**.
 2. Azure will now redeploy the packet core instance with the new configuration. The Azure portal will display the following confirmation screen when this deployment is complete.
 
     :::image type="content" source="media/site-deployment-complete.png" alt-text="Screenshot of the Azure portal showing the confirmation of a successful deployment of a packet core instance.":::
 
-3. Select **Go to resource group**. Navigate to the **Packet Core Control Plane** resource as described in [Modify the packet core instance](#modify-the-packet-core-instance). Check that the fields under **Configuration** and **Access network** contain the updated information.
+3. Select **Go to resource group**.
+
+    - If you made changes to the packet core configuration, navigate to the **Packet Core Control Plane** resource as described in [Modify the packet core instance](#modify-the-packet-core-instance). Check that the fields under **Configuration** and **Access network** contain the updated information.
+    - If you made changes to the attached data network, select the **Mobile Network** resource, and then select **Data networks** in the resource menu. Check that the data network that you modified is listed and shows as **Succeeded** in the **Status** column.
 
 ## Next steps