using System;
using System.Drawing;
using Nevron.GraphicsCore;
using Nevron.Chart;
using Nevron.ReportingServices;

namespace MyNamespace
{
 /// <summary>
 /// Sample class
 /// </summary>
 public class MyClass
 {
  /// <summary>
  /// Main entry point
  /// </summary>
  /// <param name="context"></param>
  public static void RSMain(NRSChartCodeContext context)
  {
   NChart chart = context.document.Charts[0];
   
   foreach (NSeriesBase series in chart.Series)
   {
    series.Name = series.Name.Trim();
    if (series.Name.EndsWith("-"))
    {
     series.Name = series.Name.Substring(0, series.Name.Length - 1);
     series.Name = series.Name.Trim();
    }
   }
  }
 }
}
(just copy paste the above code in the code tab of the SSRS designer)