For a change, I can write an article in english, because I suspect, this will appeal to a broader audience than usual. In fact, I think the general audience will not appreciate this article as much as the other people who could find this with a search engine. At least, I was in need of such an article yesterday when I ran into the problem. I found this article in the forums, and it helped a lot. I will add more images than were shown there, to clarify some points. Use both articles together.
So the problem – dad took the car, and managed to break off the key in the ignition of my Land Rover Discovery I, 300tdi engine. Any attempts to use tweezers failed, key was stuck in too deep. What to do? Remove the plastic cover under the steering wheel, and proceed to unscrew the two big screws that hold the ignition mechanism in place. When that’s done, carefully unplug the black thing from it’s back (at this point, you can start the car with any flat object by inserting it into the black thing, for example a screwdriver. If you hate keys as such, you can just leave everyting as is, or even modify the car by adding a start button). Also carefully remove the round loop which is the immobiliser, it’s situated right around the place where you insert the key. I write so loosely because it’s all illustrated in the linked article.
So you will find yourself with a piece like this:
Other side looks like this (this is the thing that turns and starts the car):
Remove the plastic ring around the key, to access the tumbler. The wire that goes from here is needed for the “forgot key” beeper and illumination light:
Use pliers to unplug the safety cork:
Slowly remove the cylinder and tumbler, be extra careful to not dislodge any of the small moving parts (tumblers?) in there. They are not held by anything, and if one falls out, it exposes the tiny spring, which is crucial for the whole thing to operate. Careful!
This is what you should have on the table:
Order of reinsertation is as follows:
The inside recepticle is based on a spring too, so you will need to use that cork hole to straighten the center before you can reinsert the other parts later, like this:
All you need to do, it take that broken end of the key and pull it out of the other end of the tumbler, from here:
Now you can insert a working key and see if it works, all the tiny tumblers must fall into their places when a correct key is inserted, so that the mechanism is all smooth (no protruding tumblers). Take notice that there is a ball in the key insertion hole, which looks like can be discarded. This is wrong, the ball must be in this place for the lock to work at all. If it falls out, put it back!
This is also your chance to file off any protruding things to make the key work more smoothly. If you file off too much, you can make it accept any similar key, which is actually a nice bonus, if you lose your car keys often. Nobody will know that your car can be started with your apartment key ;)
Now you can put it all back together in reverse order. Don’t forget to return the safety cork in position, and put a drop of glue on it, so that it stays in place. Accidentaly I found another article which may come into use, it’s for BMW but it looks like all cars with keys have the same story.