Got new ignition tumbler but need help.... please

[honeybee]

Hi everyone,

94 c280. Got new ignition tumbler today. I have done readings from many postings re: how to replace one.

1. turn key to accessory position
2. insert release tool into slots to release latch
3. pull tumbler out with key
4. insert new tumber in reverse order....

My problem is:
1. unable to remove the black bezel around the tumbler; I assume I need to remove it first to expose the slots, right? How do I remove it?
2. on new tumber, I don't see any slot/groove/channel to guide the release tools to the latch. The guy at MB said it is the right tumbler (VIN matched). I used the new key that comes with it, works on every locks and ignition.

I will very much appreciate any help. I don't just want to save the labour cost, more importantly is I want to learn how to do it.

Thank you and I am attaching some images.

KC