Answer
Push and hold the [Fader Controls] button on the Ion, which is next to the [Load] button above the main playback faders. The displays on the Wing will show page numbers, and the bump buttons will turn green. The currently selected fader page will have a flashing green bump button. Press the bump button above the page number you'd like to change it to, then let go of the [Fader Controls] button.
For Wings that do not have displays, you'll still see the green LEDs on the bump buttons, with one flashing to denote the currently selected page. On both wing types the top-left most fader starts with Page 1.
