How to resolve SonicOS error "Error: Deleting VAP: Virtual Access Point Group is in use by..."

The following error appears in a SonicWall UTM appliance when trying to delete a Virtual Access Point Group (VAP Group),
"Error: Deleting VAP: Virtual Access Point Group is in use by physical radio, profile or group"
This indicates that the VAP is in use and cannot be deleted.
Screenshot below shows this error, when trying to delete VAP Group "VAP Giovanni".

Steps to delete a Virtual Access Point Group in use
Step 1: Add a new VAP Group, named differently from the previous one. 
Step 2: Change the VAP in use to a different VAP Group.
Step 3: Delete VAP named "VAP Giovanni".

Steps to delete Virtual Access Point Group "VAP Giovanni", already configured on the UTM firewall controller interface.

Step 1: Add a new VAP Group. 

From the SonicOS gui, navigate to the Sonicpoints | Virtual Access Point | Virtual Access Point Groups page.
Click on "Add Group", and select the virtual address objects to be part of the new VAP Group. Name this VAP Group differently from the previous one you want to delete (e.g.  "VAP Giovanni" is to be deleted, then name the new VAP group as "NEW VAP Giovanni")

Step 2: Change the VAP in use to a different VAP Group.

• From the SonicOS Management GUI, navigate to SonicPoints | SonicPointN Provisioning Profile
• Select the SonicPointN provisioning profile in use and click on Edit.
• From the "Edit SonicPoint N Provisioning Profile" pop-up, select "Settings"
• Access "Virtual Access Point Settings" and from the pull-down menu, move the 802.11n Radio Virtual AP Group to a VAP Group different from "VAP Giovanni" (e.g. access profile "VAP Profile" and move the Virtual Access Point Settings from "VAP Giovanni" to "NEW VAP Giovanni").

Step 3: Delete VAP named "VAP Giovanni"

From the SonicOS gui, Go to "Virtual Access Point" | "Virtual Access Point Group", click on delete at the "VAP Giovanni". The Virtual Access Point "VAP Giovanni" will now be deleted because it is not currently in use by the radio anymore