How to: Remove a Chart Sheet
To delete a chart sheet from a workbook, remove it from the workbook’s ChartSheetCollection by using the ChartSheetCollection.Remove or ChartSheetCollection.RemoveAt method.
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)