How to: Remove a Chart Sheet
You can also move a chart back to the worksheet containing the source data by using the chart’s ChartObject.MoveToWorksheet method.
Dim worksheet As Worksheet = workbook.Worksheets("chartTask1") ' Create the first chart sheet. workbook.ChartSheets.Add() ' Create the second chart sheet. workbook.ChartSheets.Add(ChartType.Pie, worksheet("B2:C7")) ' Remove the first chart sheet. workbook.ChartSheets.RemoveAt(0)