I got replacement LEDs from HIDS4U when upgrading from yellow angel eyes (on a E65) to white, which then matched the xenons better, for me was an easy job one bulb per side, top, loosen headlight, shifty forward an inch and take what really doesn't look like a bulb at all out, others straight in, checked working before re-assemble - LEDS work one polarity, not the other.
As for how to, google is your friend, what's the E?? or F?? number of yours?
And might be worth a look on realoem.com with your VIN to see if there's any expanded views of that area, might be, might not be, worth a punt..
So, google;
"E?? Angel Eye upgrade" and you'll find plenty of youtube vids, watch 2 or 3 and get the general idea.
It might even be worth extracting the bad one, just to see what it looks like and give you a reference when looking at LEDs, call it practice
I wouldn't expect anything from Halfrauds, as far as Halos/Angel Eyes, more or less interchangeable, I think Angle Eyes makes quite clear what you are talking about though..
Oh and 5 series wikipedia as what yours is called
Good Luck

 

BMW 5 Series - Wikipedia

en.wikipedia.org

E61 or F11

 

Thanks so much for taking the time mate. Much appreciated.

Is this the correct sort of thing?

Angel Eyes (rings) LED pack for BMW 5 Series F10 F11 - MTEC V3.0

Discover our MTEC 2.0 Angel Eyes (rings) LED pack for BMW 5 Series F10 F11 with assembly instructions. 48-hour delivery.

www.ledperf.co.uk

H7 HIDS4U Stealth-X 35W Xenon HID Conversion Kit

HID conversion kit for your vehicle. This system uses just 35W ballasts to produce an immense 350% brighter light when compared to standard bulbs. H7 HID kits are the ultimate headlight upgrade within the automotive industry.

www.hids4u.co.uk

Looks overkill, didn’t expect the extra cabling or have I looked at the wrong thing

 

Well.... When I did mine I just got a different (but LED) bulb, plugged it in and it was canbus compliant and... worked
It was a while ago, and was on a 7 series, only cost £36, two and half, maybe 3 years later one side died, and ordered the same thing again, there have been people having problems blowing the central light control module with high wattage LED kits - couldn't see what those were on this one, also couldn't see how much they were, some are silly money for an Angel Eye upgrade...

The H7 HID conversion kit is for your headlight dip, if you have xenon not needed, it's mainly saying it's better than an earlier kit they did, did see it's HIDS4U though (also noted not suitable for use in a reflector headlight)
If you don't have xenons but poor headlights - halogens, several on here have used H7 LED replacement bulbs, advantage there is the halogen light source point is very closely matched by the H7 LEDs.
HIDS4U look like they've got out of the BMW Angel Eye upgrade market.

One of the highest value things you can do, it take the dead one out, then at least when looking at a LED replacement you stand a chance of getting the right replacement, the ledperf one may well be good for you, you could always talk to someone at ledperf, or email them, on the face of it, it does seem slight overkill, mine were ballasted, canbus compliant, all built into the bulb, and this was ages ago, could do it then, no reason why not now!

 

BMW Angel Eyes | BMW E91 E90 LED Angel Eyes Kit | Cree Led bulbs

Enhance your BMW's appearance with Xenons4U’s premium Angel Eyes. Explore a range of options and add a touch of sophistication to your vehicle's lighting.

xenons4u.co.uk

 

Swerve and avoid the 80W ones
Although commonly if Chinese sourced, they tend to add each bulb wattage to the other, so might be 2 x 40W - but still too high, those 20W seem reasonable, I think mine were 10W..

 

Cheers Thanatoid. You've saved me from buying something I didn't need there. I've contacted the above company just to ensure I don't make a mistake! Really appreciate your help on this.

Cheers Nic