Hey Col, welcome back
Push backwards on the lens of the light unit (towards the back of the car) and then the entire unit will pull out sideways from the wing. The whole light unit will still be attached to the power cable.
You don't need to unplug the unit from the cable. Just hold the back of the unit with one hand and twist the lens part with the other, and the lens part will come off. The bulb will be attached to the end of the cable (don't let the cable fall back inside the wing).
Change the bulb, and then reverse the above.
Here's a current (Sep 2022) eBay auction for a side repeater, which has good photos of the back so you can see what I mean.
[url]https://www.ebay.co.uk/itm/163990107658?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=aZxWYNHFTZ-&sssrc=2047675&ssuid=&widget_ver=artemis&media=COPY[/url]
S
Edit: Are you on Whatsapp? If so, join the V6 owner group! If you're interested I can send you a Whatsapp invite link.