$ sudo apt-get remove libpth20 

Uninstall libpth20 including dependent package

If you would like to remove libpth20 and it's dependent packages which are no longer needed from Ubuntu,

$ sudo apt-get remove --auto-remove libpth20 

Use Purging libpth20

If you use with purge options to libpth20 package all the configuration and dependent packages will be removed.

$ sudo apt-get purge libpth20 

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 libpth20 

See Also,