Get the list of zombie processes:

 ps aux | awk '{if($8=="Z") print}'

 ps aux | awk '{if($8=="Z") print}'

Get the parent process of each of the processes listed above (second column)

ps -o ppid= -p 490392

ps -o ppid= -p 490392

Kill the parent process from the above output

sudo kill -9 3167559

sudo kill -9 3167559