kindly help where i mistake

[balavaka]

Sub RenameCharacterStyles()
    Dim oldNames As Variant
    oldNames = Array("Old Style 1", "Old Style 2", "Old Style 3")

    Dim newNames As Variant
    newNames = Array("New Style 1", "New Style 2", "New Style 3")

    Dim i As Integer
    For i = 0 To UBound(oldNames)
        Dim style As Style
        Set style = ActiveDocument.Styles(oldNames(i))
        style.RenumberList oldNames(i), newNames(i)
    Next i
End Sub

[Italophile]

style.RenumberList oldNames(i), newNames(i)

The function RenumberList does not exist.

If you explain what it is you are trying to do, perhaps someone can help you.

[balavaka]

rename oldNames with newNames

[Italophile]

Originally Posted by balavaka

rename oldNames with newNames

So long as you are not attempting to rename built-in styles that's as simple as

style.Name = newNames(i)

[balavaka]

Sub RenameCharacterStyles()
    Dim oldNames As Variant
    oldNames = Array("Old Style 1", "Old Style 2", "Old Style 3")

    Dim newNames As Variant
    newNames = Array("New Style 1", "New Style 2", "New Style 3")

    Dim i As Integer
    For i = 0 To UBound(oldNames)
        Dim style As Style
        Set style = ActiveDocument.Styles(oldNames(i))
        style.Name = newNames(i)
    Next i
End Sub

[Italophile]

Either the style you are attempting to rename doesn't exist in the ActiveDocument, or you are trying to rename a built-in style, which isn't possible.

You need to add some error checking, for example:

Sub RenameCharacterStyles()
    Dim oldNames As Variant
    oldNames = Array("Old Style 1", "Old Style 2", "Old Style 3")

    Dim newNames As Variant
    newNames = Array("New Style 1", "New Style 2", "New Style 3")

    Dim i As Integer
    Dim sty As Style
    For i = 0 To UBound(oldNames)
        Set sty = ActiveDocument.Styles(oldNames(i))
        If Not sty Is Nothing Then
            If Not sty.BuiltIn Then sty.Name = newNames(i)
        End If
    Next i
End Sub

[balavaka]

compile error

on this line

If Not sty.BuiltIn Then sty.Name = newNames(i)

[Italophile]

Originally Posted by balavaka

compile error

on this line

If Not sty.BuiltIn Then sty.Name = newNames(i)

Sorry that should be

If Not sty.BuiltIn Then sty.NameLocal = newNames(i)