|I'm rusty too. Did you look in Excel Help? That's where I got this from:|
"Click the chart, and then click Source Data on the Chart menu.
On the Series tab, click the data series name you want to change.
In the Name box, specify the worksheet cell you want to use as the legend text or data series name. You can also type the name you want to use. If you type a name in the Name box, the legend text or data series name is no longer linked to a worksheet cell."
Tried it on one of my old charts and it was fine but I'm using a very old Office version.
Always pop back and let us know the outcome - thanks