$ sudo apt-get remove libygl4 

Uninstall libygl4 including dependent package

If you would like to remove libygl4 and it's dependent packages which are no longer needed from Ubuntu,

$ sudo apt-get remove --auto-remove libygl4 

Use Purging libygl4

If you use with purge options to libygl4 package all the configuration and dependent packages will be removed.

$ sudo apt-get purge libygl4 

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 libygl4 

See Also,