code: public void removeExtension() {
  
  		try {
  			if (extendedRelationsDao.isTableExists()) {
  				List<ExtendedRelation> extendedRelations = extendedRelationsDao
  						.queryForAll();
  				for (ExtendedRelation extendedRelation : extendedRelations) {
  					geoPackage.deleteTable(extendedRelation
  							.getMappingTableName());
  				}
  				geoPackage.dropTable(extendedRelationsDao.getTableName());
  			}
  			if (extensionsDao.isTableExists()) {
  				extensionsDao.deleteByExtension(EXTENSION_NAME);
  			}
  		} catch (SQLException e) {
  			throw new GeoPackageException(
  					"Failed to delete Related Tables extension and table. GeoPackage: "
  							+ geoPackage.getName(), e);
  		}
  	}
docs: Remove all trace of the extension