(Assuming you got RSS retrieval and parsing correctly) You just have to change some text in widget:
AppWidgetManager manager = AppWidgetManager.getInstance(context);
RemoteViews views = new RemoteViews(context.getPackageName(), R.name_of_your_widget_layout);
// set text of some view
views.setTextViewText(R.id.widget_amount_cameras, amountCameras);
// and of another view
views.setTextViewText(R.id.widget_location, locationCity);
// ... and yet another view
views.setTextViewText(R.id.locationStatus, locationStatus);
// get IDs of widgets , there could be more than one
final int[] appWidgetIds = manager.getAppWidgetIds(new ComponentName(YOurWidgetProviderClass.class.getPackage().getName(), YOurWidgetProviderClass.class.getName()));
// update all hte instances
manager.updateAppWidget(appWidgetIds, views);
You can change only some attributes of your widgets ( due to security constraints ) - See Javadoc of RemoteViews for further explanations