Editing a formula is the same as editing any entry in Excel. The following steps show how you do it:
Select the cell that contains the formula you want to edit.
Click in the Formula bar to place the insertion point in the formula, or press F2 to enter Edit mode (the insertion point is placed at the end of the entry in that cell).
In-Cell Editing To quickly edit the contents of a cell, double-click the cell. The insertion point appears inside the cell, and you can make any necessary changes.
Press the left-arrow key or the right-arrow key to move the insertion point within the formula. Then, use the Backspace key to delete characters to the left, or use the Delete key to delete characters to the right. Type any additional characters.
When you finish editing the data, click the Enter button on the Formula bar or press Enter to accept your changes.