I have a route plotted fine on using DirectionsRender but I cannot find out how to replace the generic Google markers with my own.
I know and use this in a normal Google
this is how you need to approach it
Declare all your image icons as shown below
var movingIcon = new google.maps.MarkerImage('/img/icon_moving.jpg');
var startIcon = new google.maps.MarkerImage('/img/icon_start.png');
Then while creating the marker, use the icon option to set the specific image to that marker
marker = new google.maps.Marker({
position: point,
map: map,
icon: movingIcon
});