I used black leccy tape and my garage door, draw up in front at a reasonable distance (say 2 metres) and on your normal elevation mark the line of the top of your lights, then using the wheels underneath your bonnet on top of your lights you can adjust your lights upwards until they are perhaps about say 1 cm, then see how they look, I adjusted my Xenons the same way as they are set stupidly low from the factory.
ATB,
Tom