Preparation: Connect to IC_204 in Vediamo. Go to ECU Identification and write down your Software Block #0 (e.g., 2049021203). You need this number for the Seed/Key calculator. You can use SeedCalc or UnlockECU for this. I personally used the UnlockECU Web version. 

STEP 1: Read Your Original Bytes (Do this BEFORE unlocking!) Do not skip this. If you unlock the ECU first, you will hit a 5-second timeout and get locked out while trying to read.

1. Open the manual command input (F12).
2. Send UDS command: 23 14 10 00 01 D0 08   (This reads the AMG menu line).
3. You will get a response like:  63 FF FF FF FF FF FF FF FF
4. Open Notepad. Copy those 8 bytes, change the first byte to FC, and build your write command. It should look like this:
   3D 14 10 00 01 D0 08 FC FF FF FF FF FF FF FF

(Optional: If you have a diesel/CNG, read line 000260 right now too: 23 14 10 00 02 60 0A. Copy the 10 bytes, change the last two to 30 60 for diesel pre-heat fix, or 30 82
for CNG fix, and prep your second write command in Notepad).

STEP 2: The Security Unlock Speed Run Now you unlock the cluster. Have your Notepad open and your

Now you unlock the cluster. 

Level 9: Send 27 09. You'll get an 8-byte seed. Put it in UnlockECU (Level 9) to get the key. Send 27 0A [Your Key]. If you get 67 0A, you are good.

Level 0D (Level 13): Send 27 0D. Get the new seed, put it in UnlockECU (Level 13) to get the key. Send 27 0E [Your Key].

WRITE FAST: The second you get the 67 0E success response, the 5-second timer starts. Immediately paste your command from Notepad and hit send.

If the ECU responds with 7D 14 10 00 01 D0 08, the flash was successful!

Send the 11 01 command and it will reset your cluster. The cluster will click, go black, and reboot with the AMG logo and menus. 
Check if the preheat diesel lamp is turned on when ignition is in 2nd position.