I dissemble the complete headlamp. Took out the reflector, the bulb bayonet cup holder and the bulb itself. I have a British pre focus main bulb fitted there. The problem is that I now don’t know the correct aligning when assembling back the lamp: there is a slot inside the bulb base that fits to the holder but I do not know the right way of them to sit inside the reflector. Is there a way to know?