I know you can read and reset abs warning lights on a disco 1 by placing a paper clip on pins 5 and 15 of the obd connector above the pedals. http://www.horodecki.pl/rajdy4x4/ABS/Jay%20Beale_%201997%20Land%20Rover%20Discovery%20-%20reset%20ABS%20warning%20light.pdf

Is there any similar way of clearing the lights on a disco 2 without going to a dealer?

The light usually disappears when the underlying fault is fixed. But unless you're a lucky guesser, without a fault code reader (nanocom/hawkeye) there's no simple trick as with the disco1 to find the fault.

David