$ sudo apt-get remove osm2pgsql 

Uninstall osm2pgsql including dependent package

If you would like to remove osm2pgsql and it's dependent packages which are no longer needed from Ubuntu,

$ sudo apt-get remove --auto-remove osm2pgsql 

Use Purging osm2pgsql

If you use with purge options to osm2pgsql package all the configuration and dependent packages will be removed.

$ sudo apt-get purge osm2pgsql 

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 osm2pgsql 

See Also,