Sorry, the old way is no longer possible. You can drag up/down or left/right to adjust the value. You can click to position the cursor and then type. You can make selections using shift+left/right, but you can't select only part of the text using the mouse. That will be the same as dragging left/right, which will change the value, not select only part of the text.
We did this because we felt that dragging to change the value was much more common than selecting part of the text using the mouse. Previously we had only dragging up/down to change the value, but this doesn't work well when the text box is near the bottom of the screen.
