My '93 500SL has had a driver's door lock barrel replacement at some stage, which does not match all the other locks. I am assuming that with all the necessary ID I can order a replacement of the correct original pattern from my nearest Mercedes dealer. However, I would appreciate any guidance on the practicalities of the changeover from anyone that has done this before. I am definitely a competent DIY merchant but I have never worked on a car lock. I don't want to find I am half-way through and then stuck unable to re-fit the old one or indeed the new one!