Deleating Invoices

Hello, i have trouble to apply this Invoice Deletion… To begin, I don’t even know how to Open /application/config/config.php. Can someone help me ?

Thank you,
David

Open /application/config/config.php and replace
$config['enable_invoice_deletion'] = FALSE;
with
$config['enable_invoice_deletion'] = TRUE;
To see the delete option in the pulldown, you also need to replace $config['disable_read_only'] = FALSE;
with
$config['disable_read_only'] = TRUE;