Special thanks to Rick Petrecca for providing the key information I needed.  The
following is the code for including popups in an extension:

>From the Make script:
'----------------------------------------------------------------
' Add in the Pop-ups which belong to the View GUI.
' Item 0 in the extension.
'----------------------------------------------------------------
theViewGUI=theProj.FindGUI("View")
myExt.Add(theViewGUI.GetPopups.FindByLabel("ARIMS"))

>From the install script:
'----------------------------------------------------------------
' Now add in the pop-ups needed for the extension.
'----------------------------------------------------------------
theViewGUI=theProject.FindGUI("View")
thePopups=theViewGUI.GetPopups
thePopups.Add(Self.Get(0),0)
theActPop = thePopUps.FindByLabel("ARIMS")
thePopUps.SetActive(theActPop)

>From the Uninstall script:
'----------------------------------------------------------------
' Now remove the pop-ups added by the extension.
'----------------------------------------------------------------
theViewGUI=theProj.FindGUI("View")
thePopups=theViewGUI.GetPopups
thePopups.Remove(Self.Get(0))