how to kill zombie process?

How to kill a zombie process on a MBP using the Terminal?

command:

ps -A -ostat,ppid,pid,command | grep -e '^[Zz]'

output:

Z 1 952 (prl_disp_service)

Z 952 1166 (prl_vm_app)

"sudo kill -s HUP 1" and "kill -9 952 1166" has not worked for me.