npm install @angularclass/hmr -D

 // main.ts
if (environment.production) {
 enableProdMode();
}else {
 if (module.hot) {
  module.hot.accept();
  module.hot.dispose(() => {
   let _styles = document.head.querySelectorAll('style');
   let styles = Array.prototype.slice.call(_styles);
   styles
    .filter((style: any) => style.innerText.indexOf('_ng') !== -1)
    .map((el: any) => document.head.removeChild(el));
  })
 }
}

platformBrowserDynamic().bootstrapModule(AppModule);

// typings.d.ts
declare var module: NodeModule;
interface NodeModule {
 hot: any;
}

// package.json
ng serve -H d.io --port 3000 --hmr --proxy-config=./proxy.json