Hi,
You can change the images of the zoom in and zoom out buttons of the pan and zoom control using the following code:
NButton zoomOutButton = (NButton)panAndZoom.Controls[1].Controls[0].Controls[1];
zoomOutButton.Image = zoomOutImage;
NButton zoomInButton = (NButton)panAndZoom.Controls[1].Controls[0].Controls[2];
zoomInButton.Image = zoomInImage;