Re: Changing sidelights.
Get a mirror and you will be able to see inside once you take the cap off the back and remove the 'easy' bulb first to get access.
There should ne a long 'extension' black lever which is hard to get at inside the headlight.
The theory is, a quarter turn and it pulls out. this has worked once for me!
In reality they can be very stiff and the lever is brittle, so it snaps off, in which case you need 2 hours, patience and long nosed mole grips to extract whats left of the lampholders.
And it is a H6W with offset pins, so the lamp only goes in one way round, so be careful. Turn the sidelights on when re-assembling, it makes things easier, as does a thin pair of gloves to stop your knuckles getting skint.
Gazza 82 must have very small hands.....