Your car does not have the orifice tube, it uses an expansion valve. It can be seen besides the brake booster. If you follow the big chunky A/C suction from the compressor to the firewall insulation you will see that it leads into a rectangle block which has another thinner line (liquid) on it too. That is the expansion valve.
Your next question would be how do I get tools into that microscopic location
easy - think like MB design - remove the lower rubber weatherstrip from the windshield - (pull it out) - pull out the little white locking piece that holds the two plastic wiper trays together and keep it safe. remove the screws from the plastic pieces and remove the items - they come out easily
You now have all the room you want to work the tools - If your mechanic is not accustomed to MB repairs - tell him this - it will make work easier and prevent other damages like the vacuum line bundles near it.
Always use a genuine expansion valve. Also make sure your mechanic sets the A/C compressor clutch gap correctly. If its not correct even on a new compressor - you will be paying him a visit again soon.