Again if you are in a situation that your enemy is about to harm you or your family and you have a fear of life, you can do this wazifa. Please make sure that Shariat allows you to do this.
Take a brick and go next to a river. Read Surah Yasin 41 times with the intention of your enemy to die. while reading it think of your enemy dying.
Each time you will finish Surah Yasin you will make a line on that brick to count. Take a nail or a knife to do that. Once you have made 41 lines, facing the kibla, throw that brick in the water.
Do Not read bismillah or Darood / Salavat with this wazifa.
Allah will kill him himself.
If you are wrong according to shariat then you will die instead. be careful.