<label class="radio">
                                <input class="bild-switch_1a" type="radio" name="bilder" value="Bild1" data-image="Bild1.png" onchange="RadioButton('Bild1.png', [733, 152])" checked/>Bild 1
                             </label>...

function RadioButton(url, size){
    newL = new ol.layer.Image({
        source: new ol.source.ImageStatic({
            url: url, 
            imageSize: size,
            projection: proj,
            imageExtent: proj.getExtent()
        })
    });
    map.removeLayer(layer);
    var allLayers = map.getLayers().getArray()[0];
    map.removeLayer(allLayers);

    for(var i = 0; i<icons.length; i++){
        map.removeLayer(icons[i]);   
    }  
    map.addLayer(newL);
    map.updateSize();
};