After my (r) LED headlight array conked out 3 years ago following a rain storm, I finally decided to dig in and replace the thing. I had purchased an old light off ebay so had the needed parts.
The procedure was a 4 part process using a number of ideas put forth by previous individuals on this site. I have added my own observations and experience with this project to pass on. Pics attached
Part 1; Pulling the headlight
1. jack up, remove wheel, fwd underbelly tray. blue masking tape off the lens, perimeter of lens on the hood and the wheel arch. Use the 3m tape as per the pic. It never leaves a residue. this prevents scratching
2. use phillips and T30 to remove screws on the wheel well liner. Careful with how the liner jogs in with the 'valence' on the bumper . The valence is a right angled piece of plastic along the front of the bumper
3. I did not remove all the wheel well liner T30's at the back and underside at the back; not needed (see pic). this made it easier to realign the thing and not have to maneuver a big hunk of plastic.
4. remove connections; maf, position light, headlight (headlight connection is tricky; it is hard to see and requires the ret tab to be pushed out ALL THE Way. I took a small screwdriver and pushed in the 2 ears into the fitting to ensure it was in unlock position. Partial push out and what looks like success may not be the case
5. for the air box, i removed the black plastic clamp at the top of the box (threw it away and used a ss hose clamp as per BMW Norths suggestion). I then removed the 3 screws holding the box and got under the vehicle and wiggled out the bottom hose (the bottom s not clamped it is pressed in. the air box then dropped/pulled out.
5. loose wires are tied off out of the way to prepare to pull the large hunk of plastic which is the headlight. However there are some strange, zap strap type anchor clips attached to the headlight which need prying off to free up the wiring. these are odd connectors and on 2 i ended up cutting the zap strap and rerouting new zap straps in place
6. once the airbox is out you can easily see the washer hose and push out the U clip to release (dont lose it)
7.. remove the 3 headlight bolts; 1 at the front accessed via underside of car and 2 at the back accessed via the wheel well
8. the headlight at that point just dropped out. No fighting there

Part II Removing the lens
1. I removed my protective blue tape, pulled the HID bulb and put the light into a cardboard box with a hairdryer (approx 2000w) for 10 min. All other components were left in place except the headlight washer mechanism. this inhibits removal of the lens. remove it by unscrewing 2 screw at its attachment point on the underside of the light
2. I used a heat gun to soften and bend back the retention tabs so that they were unclipped. In some cases I wedged in small flathead screwdrivers or zap straps to keep the tabs undone
2. using a screwdriver, I gently prised the lens off. Take your time. I found that once it started to come, it all came off. You will likely find a weak point in the glue and it was almost a domino effect after that
3. clean the inside of the lens thoroughly and set aside. you dont want dust and debris on the inside when you are hastily trying to reassemble the thing
4. clean the lens channel of old butyl; it should just pull out, then clean the channel with a shop towel lighly dabbed in acetone runing a flathead screwdriver around the perimeter. do the same for the mating surface of the lens

Part 3 Replacing the LED lights and board
to access the board, you need to remove the led array which sits on top of it
1. remove screw on bottom of housing; this retains the black cowling and has to be removed to get at the hidden LED screw.
2. remove top led array silver screw (5.5mm)
3. lift up the top of the led array and concurrently lift out the black cowling. this reveals the bottom silver led screw
4. the led array is perm connected to the board. move it as wires permit to the side and unscrew the 2 black 5.5mm screws holding the board in place
5. unclip the 2 wire connections to the board
6. insert new board and led array as a unit and reverse disassembly including the bottom screw for the cowling

Part 4 Resealing the Lens using Morimoto retro Butyl Rubber
watched a lot of videos on this procedure and had to modify what I learned for application to the material at hand
First, The Morimoto is a big chunk of butyl. You need to stretch it out by hand to fit the relatively small lens channel. Many videos I saw on the topic had lights with much larger channels. The Morimoto needs to be layed into the channel so that there is enough to seal the unit but not so much that it obstructs the lens from being relatched. This is a bit of a guess job
Second. I applied the Morimoto at room temp. Trying to apply after it was heated up even for a few min, made it a goopy, unwieldly mess
procedure
1. lay out room temp morimoto into the channel if possible as one long piece
2. preheat oven to 220 F, put the housing minus lens into the oven for 7 min. Make sure oven is preheated. I put housing on 2 2x4's in the oven rack. I left all light components in place other than the HID bulb. This included the ballast, LED array, board etc
3. Pull from oven, keep oven on, apply (CLEAN) lens to housing, press in place as best you can, return to oven for further 7 min
4. Remove from oven, clamp down, reclip and let it sit for min 3 h. clamps are a good idea. If you dont have clamps at the ready, use the clamps from your battery charger of if in a bind, hemostats or bungie cord. vice grips wont hold it
As a secondary precaution after all was said and done i stretched out more Morimot and applied to to the perimeter of the seal, pushing it into the joint and then heat gunning it to flow it (may not be needed if you get the right amount inthe channel to begin with

Return fixed unit to vehicle. Done
As one further step, I drilled out a 11mm hole in the back of the light access panel and applied a Morimoto bolt on breather. ?Prophylaxis for moisture. We will see
Hope some of this helps. Certainly a learning experience. I learned a great deal from others posts on the topic both directly to the point and also regarding removal of components to access the light.



flapped back wheel liner. lots of room for big hunk of plastic light

 

Great write up. I hope I never need it

 

Great info, thanks for sharing. I think most (myself included) would be interested in finding a professional shop do the repair work stateside, as mentioned in the other thread.

 

Excellent write up...just in time for me...I’m about to do the same job!! I’ll send you list of what I’m going to work on next if you feel like doing more of these

 

if you get stuck on something, contact me. My project took me 2 days but i think I could do it now in a couple of hours