Sounds like you are not wanting to do the job, and a little concerned over the cost.
I have paid people to do things that I just do not want to do. No shame in that... We all make choices.
If cost is a concern, and you have a little free time. Talk to the local High school auto shop teacher. Maybe he would help have the students change them, while you instruct and teach, and they experience some German engineering. And they usually do not charge anything.
Who knows, May inspire a new MB diesel nut.
these cars can be in their price range. And I woulod have never thought of one at that age.

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83 300SD Dark Silver Dark brown inside