Type the wrong text in?
One you deleselct it or click elsewhere, its stuck.
So just press CTRL+Z to undo it
If you still have the text active, the arrow keys will let you go back and delete the wrong
character, and/or add a capital letter
Another trick - use the dropper to sample the font colour, then use paitnbrush set at (eg) 6 pixels to broad swipe it over
or pencil at 2 pixels to careful over write it.
I use this trick to change the dialogue text boxes in screenshots of software, cos writing manuals is wot I does, like.