I figured it out.
this script will remove old network printers, add new network printers and set default printer to a network printer if a local printer does not exist.
On Error Resume Next
Dim OldPrint, UNCpath1, UNCpath2, UNCpath3, UNCpath4, NewPrint, strComputer, objWMIService, LocalPrinter
UNCpath1 = "\\Fileserver\BrotherW6th"
UNCpath2 = "\\Fileserver\CanoniP6"
UNCpath3 = "\\Fileserver\HPLaser2015"
UNCpath4 = "\\Fileserver\OKIC5300"
Set OldPrint = WScript.CreateObject("WScript.Network")
OldPrint.RemovePrinterConnection UNCpath1, true, true
OldPrint.RemovePrinterConnection UNCpath2, true, true
OldPrint.RemovePrinterConnection UNCpath3, true, true
OldPrint.RemovePrinterConnection UNCpath4, true, true
Set NewPrint = CreateObject("Wscript.Network")
NewPrint.AddWindowsPrinterConnection "\\Fileserver2\BrotherW6th"
NewPrint.AddWindowsPrinterConnection "\\Fileserver2\CanoniP6"
NewPrint.AddWindowsPrinterConnection "\\Fileserver2\HPLaser2015"
NewPrint.AddWindowsPrinterConnection "\\Fileserver2\OKIC5300"
strComputer = "."
Set objWMIService = GetObject("winmgmts:\\" & strComputer & "\root\cimv2")
Set LocalPrinter = objWMIService.ExecQuery("Select * From Win32_Printer Where Local = TRUE")
If LocalPrinter.Count = 0 Then
NewPrint.SetDefaultPrinter "\\Fileserver2\HPLaser2015"
End IF
WScript.Quit