1985 sunroof repair?

[tshih]

Over last weekend while showing the car the sunroof failed to close because the wind deflector doesn't slide downward as the roof closes. One part that appears to be brittle and broke into smaller pieces were the two black plastic pieces near the deflector plate (on either side). anyone have had to make this repair before and how difficult is it to do. I've ordered the parts from Pelican (less than $4). Car is 1985 Carrera.