You can edit Chart Data for any instrument you like.
Right-click and select Data Editing > Edit data from the context menu to go into Edit data mode.
The Edit Bar

Note: the bar will then be edited in the current Chart only. To change the server history, use the Export to Server function.
Remove Bars
You can remove bars from the chart by right-clicking and selecting Data Editing > Remove bar or selecting the appropriate option in the Data Editing toolbar after selecting the bars to be removed in Edit data mode.
Apply changes
Right-click and select Data editing > Apply changes or select the appropriate option in the Data editing toolbar to exit Edit data mode and save the bar values.
Cancel changes
Right-click and select Data Editing > Cancel changes or select the appropriate option in the Data editing toolbar to discard all changes made and exit Edit data mode.