I believe what your car needs are called "track rod mounts". They cost about $60 each and there are two of them.
I replaced the ones on my wifes 1983 300SD myself. Nothing special in doing it. You should have the car alligned after installing them. Midas did mine for $39.95.
A friend of mine had them installed at a small auto repair shop in East Tennessee. Name of the town? Parrotsville, Tn.So I don't think anything special is required. Good luck.
Bill Lewallen Lexington,Ky.