Remove

<div id="map"></div>
<script>
    $("#map").kendoMap({
        layers: [{
            type: "marker",
            dataSource: [
                { latlng: [42.3601, -71.0589], name: "Boston" },
                { latlng: [40.7128, -74.0060], name: "New York" }
            ],
            locationField: "latlng"
        }]
    });

    var map = $("#map").data("kendoMap");
    var markerLayer = map.layers[0];
    
    console.log("Markers before remove:", markerLayer.items.length);
    
    // Get the first marker and remove it
    var firstMarker = markerLayer.items[0];
    markerLayer.remove(firstMarker);
    
    console.log("Markers after remove:", markerLayer.items.length);
</script>