You can do it one of two ways: use Replace instead on Split:
Dim output as String = sourceString.Replace("occupation=""farmer""", "")
Or remove the string from the list in a loop
For i As Integer = 0 To arrayOfStrings.Length - 1
If arrayOfStrings(i) = "occupation=""farmer""" Then
arrayOfStrings(i) = ""
End If
Next
To concatenate is simple:
vXMLStream = String.Join(" ", arrayOfStrings)