I changed front rotors on my 1985 10 years ago and don't recall having to remove the hub. Indeed, I checked the wheel bearings several years ago and know that was the first time because I noticed the "clamp nut" instead of the "cotter-pin castle nut" on my old Mopars.

Like many Euro cars, the rotor is secured to the front of the hub w/ a large Phillips-head screw. You might need penetrating oil and an impact screw-driver to free it. If you end up having to drill it out, I doubt that screw is needed and was just a factory aid. Most American factories used a thin push washer you can break off and toss. The wheel studs secure the rotor. A missing screw would very slightly affect wheel balance though.

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1984 & 1985 CA 300D's
1964 & 65 Mopar's - Valiant, Dart, Newport
1996 & 2002 Chrysler minivans