1990 Mercury Topaz Repair Question
I need to replace the drivers and passenger door locks
Remove door trim panel and watershield. Refer to Section 01-05.
Remove clip retaining lock cylinder rod to lock cylinder.
Pry lock cylinder retainer out of slot in door.
Remove lock cylinder from door.this clip may be hard to put on you will normally need like large screwdriver to poundit on from teh back. the rod will be held by a clip, if it's missing they are readily available at auto parts stores, ther eis a left and right side to the clips.
there will be a thing that the button or door handle hits against. alot of times just lubing it with penetrating oil or wd40 willfree it up along with working it back and forth by hand
lyube all the stuff in the box if you can as well as linkage. this drawing is from a 92 but close enough for yours. if the sheet metal h as been pounded out by lock you'll need to fix that before installing the new ones.