How to change the row and column header values?

<UserControl.Resources>
<Utils:TextConverter x:Key="textConverter"></Utils:TextConverter>
<Style x:Key="colStyle" TargetType="syncfusion:OlapGridTemplateCell">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="syncfusion:OlapGridTemplateCell">
<StackPanel Grid.Column="1" Orientation="Horizontal" Background="#4A88C6">
<!--Text block-->
<TextBlock Grid.Column="1" Margin="3,4,4,0"
Text="{Binding Converter={StaticResource textConverter}}"
TextWrapping="Wrap" HorizontalAlignment="Center"
VerticalAlignment="Center" FontFamily="Calibri" FontSize="12" MinWidth="75" />
</StackPanel>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</UserControl.Resources>
<syncfusion:OlapGrid Height="400" x:Name="olapGrid" FreezeHeaders="True" VisualStyle="Office2007Blue" OlapDataManager="{Binding OlapDataManager}" >
<syncfusion:OlapGrid.ColumnHeaderStyle>
<syncfusion:OlapGridCellStyle Style="{StaticResource colStyle}"/>
</syncfusion:OlapGrid.ColumnHeaderStyle>
</syncfusion:OlapGrid>

public class TextConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
string text = null;
PivotCellDescriptor cellinfo = value as PivotCellDescriptor;
if (cellinfo != null)
{
switch (cellinfo.CellValue)
{
case "Australia":
text = "Aus";
return text;
case "Canada":
text="Can";
return text;
case "France":
text = "Fran";
return text;
case "Germany":
text = "Ger";
return text;
case "United Kingdom":
text = "UK";
return text;
case "United States":
text = "US";
return text;
}
}
return text;
}
public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
throw new NotImplementedException();
}
}

Public Class TextConverter
Implements IValueConverter
Public Function Convert(ByVal value As Object, ByVal targetType As Type, ByVal parameter As Object, ByVal culture As System.Globalization.CultureInfo) As Object
Dim text As String = Nothing
Dim cellinfo As PivotCellDescriptor =  value as PivotCellDescriptor
If Not cellinfo Is Nothing Then
Select Case cellinfo.CellValue
Case "Australia"
text = "Aus"
Return text
Case "Canada"
text = "Can"
Return text
Case "France"
text = "Fran"
Return text
Case "Germany"
text = "Ger"
Return text
Case "United Kingdom"
text = "UK"
Return text
Case "United States"
text = "US"
Return text
End Select
End If
Return text
End Function
Public Function ConvertBack(ByVal value As Object, ByVal targetType As Type, ByVal parameter As Object, ByVal culture As System.Globalization.CultureInfo) As Object
Throw New NotImplementedException()
End Function
End Class