I had the same problem and took one off a spare disco in my mates yard in the dark. When I got it back into the workshop it was melted as bad as the one I was taking off.
Scratching my head for a minute I realised its not a landrover part - any car using 3 pin halogens of that type uses the same connection. I promptly whipped one off a Citroen and voilà , le Disco sorted :)