Point and Click Formula Editing

You can use a similar approach to edit formulas, although it's slightly trickier.

1. Move to the cell that contains the formula you want to edit, and put it in edit mode by double clicking it or pressing F2.
   Excel highlights all the cells that this formula uses with a colored outline. Excel's even clever enough to use a helpful color-coding system. Each cell reference uses the same color as the outline surrounding the cell it's referring to. This can help you pick out where each reference is.
2. Click the outline of the cell you want to change. (Your pointer changes from a fat plus sign to a four headed arrow when you're over the outline.) With the mouse button still held down, drag this outline over to the new cell (or cells) you want to use.
   Excel updates the formula automatically. You can also expand and shrink cell range references. To do so, put the formula holding cell into edit mode, and then click any corner of the border that surrounds the range you want to change. Next, drag the border to change the size of the range. If you want to move the range, then click any part of the range border and drag the outline in the same way as you would with a cell reference.
3. Press Enter or click the formula bar checkmark to accept your changes.
   That's it.