To rename a data series in an Excel chart, please do as follows:

1. Right click the chart whose data series you will rename, and click Select Data from the right-clicking menu. See screenshot:

2. Now the Select Data Source dialog box comes out. Please click to highlight the specified data series you will rename, and then click the Edit button. See screenshot:

3. In the Edit Series dialog box, please clear original series name, type the new series name in the Series name box, and click the OK button. See screenshot:

Note: If you want to link the series name to a cell, please clear original series name and select the specified cell, and then click the OK button.

4. Now you return to the Select Data Series dialog box, please click the OK button to save the change.
At present, you can see the specified data series has been renamed. See screenshot:

You can repeat the above steps to rename other data series as you need.

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