To uninstall x11proto-core-dev just follow these instructions.
sudo apt-get remove x11proto-core-dev
This will remove just the x11proto-core-dev package itself.
sudo apt-get remove --auto-remove x11proto-core-dev
This will remove the x11proto-core-dev package and any other dependant packages which are no longer needed.
If you also want to delete your local/config files for x11proto-core-dev then this will work.
sudo apt-get purge x11proto-core-dev
Or similarly, like this x11proto-core-dev
sudo apt-get purge --auto-remove x11proto-core-dev
|Maintainer||Debian X Strike Force <firstname.lastname@example.org>|
|Description||X11 core wire protocol and auxiliary headers for the core X11 protocol, and also provides a number of utility headers, used to abstract OS-specific functions.|