Unable to lock the administration directory (/var/lib/dpkg/) is another process using it?

First Process:

First catch the process containing the word apt. Then kill the process.

ps aux | grep apt

Then

sudo kill -9 processId.

Second Process:

You can delete the lock file with the following command:

sudo rm /var/lib/apt/lists/lock 
 
You may also need to delete the lock file in the cache directory

sudo rm /var/cache/apt/archives/lock
sudo rm /var/lib/dpkg/lock 
 
After that, try opening Synaptic again.

Resource Link: https://askubuntu.com/questions/15433/unable-to-lock-the-administration-directory-var-lib-dpkg-is-another-process/315791#315791