You can enable or disable any apache module in Ubuntu using a2enmod and a2dismod, Not need to edit configuration file.
Run the following command from root user To enable/disable a module:
#a2enmod module_name
#a2dismod module_name
To enable modules
#a2enmod expires
#a2enmod headers
#a2enmod rewrite
#a2enmod mod-security
#/etc/init.d/apache2 restart
#a2enmod headers
#a2enmod rewrite
#a2enmod mod-security
#/etc/init.d/apache2 restart
To disable a module:
#a2dismod module_name
#a2dismod expires
#a2dismod headers
#a2dismod rewrite
#a2dismod mod-security
#/etc/init.d/apache2 restart
#a2dismod expires
#a2dismod headers
#a2dismod rewrite
#a2dismod mod-security
#/etc/init.d/apache2 restart
Enjoy!
