$ sudo apt-get remove pgagent 

Uninstall pgagent including dependent package

If you would like to remove pgagent and it's dependent packages which are no longer needed from Ubuntu,

$ sudo apt-get remove --auto-remove pgagent 

Use Purging pgagent

If you use with purge options to pgagent package all the configuration and dependent packages will be removed.

$ sudo apt-get purge pgagent 

If you use purge options along with auto remove, will be removed everything regarding the package, It's really useful when you want to reinstall again.

$ sudo apt-get purge --auto-remove pgagent 

See Also,