You can double-click on the cell,move the cursor to the end of the data you
want to delete and press backspace until it is gone. Then press the enter key
to complete the edit.
Just to clarify. The reason I would be inclined to use a formula is that I
have an aversion to deleting things. If you delete the trailing text there is
no way to get it back. If somewhere in the 25,000 records some of them go
wrong for some reason or you just want to see what it used to look like then
you are in trouble with a replace.
Jim's formula works regardless of the length of the measurement. In his
example, it will return all the characters in A1 from the first character
through the "s" in the word radius. FIND("radius",A1) returns the position
within the contents of A1 where the word radius begins. The +5 is to include
the rest of the word radius.