To Break Up a Dimension Element

  1. Select the dimension element(s).
  2. Select the Drop Dimension Element tool.

    The tool has no effect on selected elements that are not dimension elements. If none of the selected elements is a dimension element, the message ?Nothing to drop? is displayed in the status bar.

You can also break up a dimension element by first selecting Drop Dimension Element tool, then selecting the dimension, and then entering a data point to accept the drop.