HTC Desire interchangeable power adapter

[Guest roscoe141]

I really need an answer before I leave for holiday tomorrow morning.

It's just the stock Charger I got with my HTC Desire from Orange. It comes with an interchangeable plug slider for UK and European plug sockets.

I've managed to slide the 3 point UK plug off without any problems but can someone please tell me how to swap the British connection for the European 2 point plug connection please??