DRLs can be activated/deactivated by using the headlamp lever.
Ignition off. Lights to 'O'. Left turn on indicator (down) while pulling back (flashing mainbeam), switch on ignition, hold for 4 seconds or so and you should here a beep. The DRLs are now off.
To reactivate is similar but you use Right turn on indicator (up) instead.
Its also in the manual