Final answer:
The method that is not used to edit a formula is double-click the cell. The other three options are all valid formulas editing methods.
Step-by-step explanation:
The method that is not used to edit a formula is Double-click the cell. Double-clicking a cell activates the edit mode for the cell content, but it does not specifically edit the formula itself. The other three options - clicking the formula bar, using formula autocomplete, and pressing F2 to start edit mode - are all used to edit a formula.