Always wanted to get a set of these for my old 3 Series, but never managed in the end, so it seems like a worthy first mod for the 5. I'm sure you've seen the Angel Eye rings on modern BMWs and for older models without them you can buy whole replacement light clusters [£100+], or CCFL kits, which are rings that fit into you're existing headlight lenses. The latter are much cheaper, but they're fiddly to fit. They are approved by BMW though and are European E-Marked, so they're totally road legal. They were about £50 when I had my E36, so I'm glad to see they've nearly halved in a couple of years and I scooped mine from lightspeed_123 on eBay for £27.99 delivered! A bargain for the high-quality and finish of the kit - even the packaging was posh.
The kit didn't include any instructions though and it gets quite tricky fitting them, so after a lot of web trawling I managed to find some instructions for a similar kit fitted on a 3 Series, but with only limited references to the E39 5 Series. It served as a starting point, but with no dedicated guide for E39 readily available I've decided to jump straight out of the ScoobyLab into the fire, with my own How-To guide.
REMOVING THE HEADLIGHT:
1. Remove the 5 wiring-loom sockets from the back of each headlight.
2. Remove the 4 screws holding the light-cluster in place, located on the slam-panel and down the back of the cluster, using an 8mm wrench.
3. Pull the light-cluster forward from the inner side until the lug on the outer corner can be slid out and the cluster removed.
4. Slide off the strip of body-coloured trim and rubber seal from the bottom of the headlight.
FITTING THE RINGS/INVERTERS:
5. Remove the back of the headlight to expose the lenses by lifting the 6 clips with a screwdriver - 3 along the bottom, 2 on top and 1 on the inner edge, the last one is between the outer edge and the back of the corner-indicator - then gently prize the headlight apart.
6. Place the CCFL rings into the front part of the headlight and secure them with tape temporarily. Apply a blob of clear silicone-sealant to each end of the rings and another at the bottom. [If you're rings are one-sided, like ours, make sure the metal side is facing inwards.]
7. Connect the rings to the inverter by clipping the wires together.
8. Using glue, or sticky-pads if they come with your kit, secure the inverter box into the gap at the inner end of the headlight.
9. Run the 4 wires along the top of the glass and loop the rest round in the gap with the inverter until nothing is overhanging, then secure them with tape.
10. When the sealant has dried, remove the tape holding the rings and clip the back of the headlight back into place. Run the Red/Black wires from the inverter box through the drain plug on the inside corner of the headlight back, by removing the rubber drain spout, feeding the wires through the hole and then the spout as you replace it.
11. Replace the rubber seal and strip of body-coloured trim.
WIRING INTO THE EXISTING SIDELIGHTS:
12. Cut the wires to the sidelight socket and strip the ends. This is the plug with 2 round female sockets - the wires are Brown (-) and Grey (+) w/ a Blue stripe on O/S, Brown stripe N/S.
13. You'll need about 8" of wire reach from the drain-spout, so if necessary extend the Red/Black wires. [I just added two lengths of Blue/Brown 240v wire, used blue crimp-connectors to join them and sealed them with heat-shrink tube.]
14. Slide the two wires from the headlight through the 3mm hole on the edge of the radiator nearest the top and reverse the headlight removal procedure. Pull the wires from the inverter tight through the hole as the headlight is slid into its mount.
15. Connect the wires from the inverters to the sidelight wires using crimp-connectors or solder, then seal them with heat-shrink tube or electrical-tape. Plug the 4 remaining sockets back into the headlight and cover the old sidelight socket on the headlight with elec.- tape.
** It'll take about 60 seconds for the rings to reach full brightness the first time they're switched on.
Phew, a long process then, but worth it for the looks and the age it takes off the car I'm sure you'll agree!