How Do I Remove Blank Lines In Text Cells In a Numbers Worksheet?

I have a worksheet of text in Numbers where some cells have a blank line between the text. How do I run a routine across the whole worksheet to remove all the blank lines as I can’t seem to make ‘Find/Replace’ achieve this. Thank you.
I am trying to make the worksheet easier to read as some of the cells are very long.
—–
Brian Bennis