Increasing dynamics

Is there a way to adjust dynamics after they've been placed? Or is the only option to delete and add anew?

For example, I placed a piano dynamic marking on a note, and after listening to playback decide it needs to be changed to mezzo piano. Tried double clicking and typing, pressing up/down arrow keys, pressing the new dynamic while the old dynamic is selected. None of them worked. No forums searches have led to anything either. Any suggestions?