Thanks RIKBEL and Jussi, but your suggestions do NOT remove the first incorrect tempo designation - the result is that I get TWO tempo designations after each other.
Then, simply, delete the wrong one or edit it.
To delete it, do as you would do in a word processor: either select it with your mouse and press Del or Backspace, or move the cursor after the item and press Backspace.
To edit an item on a staff, be it a note, time signature or tempo change, just select it and press Ctrl+E. In case of a tempo indication, input the new tempo and click OK.
If it still remains, check to see if it's on a different staff that has been layered. Use View/Allow layering to delayer temporarily.