Customizing the Customer Portal "Submit a Ticket" form (not Agent ticket form)

Customizing the Customer Portal "Submit a Ticket" form (not Agent ticket form)

Hi, 

In the FREE version, I'd like to remove the Priority and Classification fields of the Customer Portal "Submit a Ticket" form.

Please note, this is not the Agent Ticket Form, it's the Portal form. 

Is there a way to do this? 

Thanks!
Rob