Delete links to external sources and retain formulas in cells.

Change

NewName:=ThisWorkbook.wbk

to either

NewName:=wbk.Name

NewName:=ThisWorkbook.Name

depending on which you mean.

The important thing that you have not stated is where you want the links to point to. There are three choices: The activeworkbook (the workbook with the Links), ThisWorkbook (the workbook with the code) or wbk, which is a workbook named Book2.xlsm (you used Set wbk = Workbooks("Book2.xlsm") ) - or a fourth, which is another workbook altogether.

Whatever you do, you need to make sure that the sheet names in the workbook are the same as in the current linked workbook - try each of these three:

Option Explicit

Sub DeleteLinks1()

    Dim strLinkNames()  As Variant
    Dim i               As Integer
    Dim wbk As Workbook
    Set wbk = Workbooks("Book2.xlsm")
    
    
    strLinkNames = ActiveWorkbook.LinkSources(xlExcelLinks)

    If Not IsEmpty(strLinkNames) Then
        For i = 1 To UBound(strLinkNames)
            ActiveWorkbook.ChangeLink _
                  Name:=strLinkNames(i), _
                  NewName:=wbk.Name, _
                  Type:=xlExcelLinks
        Next i
    End If

End Sub

Sub DeleteLinks2()

    Dim strLinkNames()  As Variant
    Dim i               As Integer
    Dim wbk As Workbook
    Set wbk = Workbooks("Book2.xlsm")
    
    
    strLinkNames = ActiveWorkbook.LinkSources(xlExcelLinks)

    If Not IsEmpty(strLinkNames) Then
        For i = 1 To UBound(strLinkNames)
            ActiveWorkbook.ChangeLink _
                  Name:=strLinkNames(i), _
                  NewName:=ThisWorkbook.Name, _
                  Type:=xlExcelLinks
        Next i
    End If

End Sub

Sub DeleteLinks3()

    Dim strLinkNames()  As Variant
    Dim i               As Integer
    Dim wbk As Workbook
    Set wbk = Workbooks("Book2.xlsm")
    
    
    strLinkNames = ActiveWorkbook.LinkSources(xlExcelLinks)

    If Not IsEmpty(strLinkNames) Then
        For i = 1 To UBound(strLinkNames)
            ActiveWorkbook.ChangeLink _
                  Name:=strLinkNames(i), _
                  NewName:=ActiveWorkbook.Name, _
                  Type:=xlExcelLinks
        Next i
    End If

End Sub