replacing pollen filter on a late mk.6 Transit?

I have just done a service pack on my 06 plate mk.6 transit swb t280, but find myself struggling with the pollen filter. I understand that it is under the engine bulkhead,below the windscreen cowling, and i think i have located the filterbox, but i can"t find any removeable panel to change the filter. Can anyone help? thanks

Paul M
October 2009