upgrade to 4.06 and php.ini MyWQL question

Hi all I just upgraded to PHP 4.06 on my Cobalt Raq 4. In the instructions it tells you: "If you use mysql with php, please note you need to add a line 'extension=mysql.so' to /etc/httpd/php.ini to load the mysql php-module." Does anyone know where this line is to be inserted? Are the single quotes to remain? Should I reboot the Raq for these changes to take? Thanks for your advice. Frank