Every Lotus Elise S1 is equipped with a nice Stack display which radiates Amber colored light. Then the 340R was introduced with a blue Stack display....
Marco Zamponi got impressed and started to think of a way to get his Stack radiating Blue light....

As Marco is in Italy and I am in Holland, it was hard to get the complete story. However, I didn't want to keep this information for myself, so here it is.. the Blue Stack Story (BSS)..

First, you'll have to get the Stack display out of its place...

To do so, you'll have to start removing the Steering Wheel Column. As you can see in the illustration (all illustrations in this article come from the Lotus Elise Workshop Manual) you'll have to remove the three screws at the bottom, holding the Column Lower Shroud and those screws holding the Column Upper Shroud.

When done, tilt the Column Upper Shroud a little and pull it towards you. It will pop out and the Column Lower Shroud can be found at your lap...

Got a tip from John Barstow, he advised to change the procedure slightly. First remove the Lower Shroud, then unscrew the bolts that hold the Instrument & Cowl mounting bracket. That will give you more room to remove the Column Upper Shroud.

Time to get the Stack display out!

Remove the two bolts at the underside of the two columns which are attached to the rear of the instrument pack. This will release the display itself.

Then gently pull out the connector. Take care, be patient and find the latch. When you've opened the latch, pull it out carefully.  If you damage the connector or one the wires, you might end up in tears!

 

Now you'll have the remove the Instrument cowl from the display by removing four nuts at the rear of the display you can see that in below picture. (All pictures have been made by Marco, thanks again for sending them!!)
Next picture is to display the different screws and nuts at the rear of the Stack Display. Remove both the red circled screws and the yellow circled nuts.

When all screws and nuts are removed, you should be able to open the Stack Display Unit. Gently pull the back from the unit and give the area where the big black connector resides some extra attention..

Now, the spooky bit starts... In nine out of ten cases, you'll have to remove the glass at the front of the Stack Display Unit....

According to Marco, it must be possible to separate the needles from the instruments...
Well.. I don't know, as you can't reach if from behind, I suppose the only way to get the board out is to remove the needles from the instruments and that means.. you'll have to remove the glass..
I'd advise you to talk to a glass supplier BEFORE opening the Stack display!

To avoid any misunderstanding: this conversion is tricky and I take no responsibility what so ever when you break the glass or when things go wrong!!

Marco told me that the glue which holds the glass needs to be cut from the front of the unit. This glue is quite hard, so absolute patience is needed here!
When you finally got the glass out (well if you succeeded, PLEASE put it somewhere where you don't break it ;) you can gently remove the needles from the instruments. Now you can take out the mainboard from the Stack Display Unit.

In the picture below, you see an open instrument and the place where the (closed) instrument normaly resides:

If you can see above items, you've opened the Stack up as far as you needed to! Congratulations.

Next part is placement of the LED's. Whatever color you choose (you can choose from Red, Yellow (instead of Amber), Blue, Green, Blue/Green and White) you need to get the right LED's. Basically these are 5mm (T1/4) transparent high intensity LED's. As you can adjust the intensity using the pushbutton on the steeringwheel shroud, I'd suggest to take the highest intensity you can get.
One more thing to choose from: opening angle.. As the LED's are shining towards the (painted) glass surface and the light is beeing transported by the paint on the glass, you need to get the biggest angle. This is something which can't be seen at the LED itself, you need to have a specification! (you can take a look at EBV's website. There is a line-chart section where you can find suppliers of Opto Electronics like Vishay, Agilent and Infineon. (By the way, EBV won't sell you the LED's directly as they are in the high volume arena..

If you have never done any soldering (electronics soldering), find someone who can help you! When you ruin the printed circuit board, you'll have to go to the dealer and order a new Stack Display Unit! (Then you can simply order a S2 display unit which is blue from itself ;)

Below picture illustrates the internals of the mainboard. the red circles indicate the position of the LED's. Not to forget, as LED's are diodes, thus letting current trhough in only one direction, you'll need to make sure the polarity is ok.
Reversing polarity will not harm the circuit, but if you find out that the unit isn't radiating any light when the cover was screwed back on again.. well.. fill in ;)

The yellow circles are matching to eachother. While you removed the mainboard, you've disconnected the LCD display and telltale lights. Take care of that when you reinstall the mainboard. Don't damage the connector!!!
To make sure you'd recognise a failure when you did hurt the glass... Here's a picture of the shattered window from Marco's Elise... :|

If everything went as it should, the right picture shows a Stack Display Unit for an Elise S1 with blue LED's. (Without glass). Allan from the Lotus Cars Club Malaysia helped us with this picture (and actually... this picture is the display unit from his car..

So.. what to do if you break the glass???
Try to catch the pieces before they hit the ground! (Use a towel instead of hands.. better for your health!). Stick the pieces together using tape or foil and take them along when you visit a glass shop. Normally, a glass shop should be able to provide you a replacement. Note the thickness of the material; if you get a piece of glass which is too thick, you'll never get it back in the Stack Display Unit..
When you finally have the glass, you'll need to get hold of some foil. Colour isn't important, because the only thing you need to do is to stick the foil at exactly the same place as the transparent part of the old glass.
When done... buy yourself a can of black paint and silver (or white) paint.

Start painting the glass with the black paint. Let it dry and check if it's really covered (by using a lamp or looking in the sun). When the black paint is ok, do the same procedure with the silver paint.
This last layer(s) of silver paint are needed to transport the light which is radiated by the LED's to the dials.
When the silver paint is on and it's dry'd completely (leave it alone for at least 24 hours!)

Then you can carefully remove the foil and put the glass into the Stack Display Unit. (painted side facing the dials!)

Ready... but again.. tricky!

Many thanks to Marco Zamponi from Italy (pictures) and Allan from Malaysia (hints)!