What a sod of a jpb it is on mine to change the n/s dip - Nitric has an extra relay or summat, clipped onto the battery box, immediately behind the access 'door' for the dip bulb. (The Dogmobile lacked this thoughtful, 'improvement'). Even with my ickle hands it was awkward, with a capital 'F'.
I realised these lamps are about 14 months old and as I do 20k+ a year, maybe half of it in the dark, they were about due for changing. (Aldi failed to come up with their 2 for £3.99 offer last autumn, hence no pre-emptive replacement took place).
Against my parsimoniuos nature and deep scepticism, I invested in a brace of Osram Nightbreaker Unlimited's which I have just grazed my hands afresh installing.

We shall see if they really are impressive.
Watch this space.