puzzler, I located the instructions for making the removal tool/release wire.
1) Bend a suitable length of 2mm diameter wire into a U-shape, and file a 70 degree chamfer on each end, facing inwards.
2) Insert the ignition key and turn the switch to position "1". See your Owner's Manual if you are unsure of position "1".
3) Insert the release wire into the slots on each side of the lock barrel, and push the wire in to compress the lock cylinder detents.
4) Withdraw the lock barrel and ignition cylinder using the ignition key.

If you inspect the new ignition cylinder you should be able to understand how the release wire functions to remove the existing ignition cylinder. Hopefully, you have purchased a new ignition cylinder from your local MB dealer, and aren't attempting to use some aftermarket facsimile.

As I mentioned previously, you may have to jiggle the release wire a bit. Once you remove the ignition cylinder it will be much easier next time because you will have the feel. It's important that the release wire fits into the 2 slots without too much clearance, otherwise the chamfered ends will not release the detents.

If you are unsuccessful removing the ignition cylinder you may want to check with a local shop that works on MB vehicles. The shop tech will likely have a removal tool and can remove the ignition cylinder in a few minutes. It's very simple, after you have done it once.

__________________
Fred Hoelzle