Could not get lock /var/lib/apt/lists/lock. It is held by process...

sudo apt update

[sudo] password for user: 

Reading package lists... Done

E: Could not get lock /var/lib/apt/lists/lock. It is held by process 1420 (packagekitd)

N: Be aware that removing the lock file is not a solution and may break your system.

E: Unable to lock directory /var/lib/apt/lists/

ps aux | grep -i apt

sudo kill processid

sudo lsof /var/lib/dpkg/lock

sudo lsof /var/lib/apt/lists/lock

sudo lsof /var/cache/apt/archives/lock