Op these are speical tools mercedes has. You might find a snap on or a tool guy. Ask them if they sale the instrument cluster hooks for mercedes benz. Without these hooks your going to have tough time. There no way! your going to get your hand way up the dash it soo tight. Like the other guys mention you need to have the steering wheel removed with a #30 torx bit it has to be 1/4 drive with a small inch and half extension. You need to removed the under dash panel to guide out old speedo cable. Also you need to removed the speedo cable from trans and also a few clips that hold it in place. I'll tell you its not any easy
job. You need to have the right tools. dont use a 3/8 rachet you'll never get enough room to remove steering wheelairbag, Also a 10mm allen socket 1/2 drive to remove the steering wheel. be sure to have some touch up paint or liquid paper to mark the steering wheel center. Op dont be surprised if the speedo head unit went south. Make sure its ok.
Factory Tech 14yrs MB