1982 Chevy Citation door lock hard to open

Taekk some enetrating oil and spray the door lock assy from the outside of hte car. Make sure you window is up. This is the part that is showing on the edge of the door. Spray it all around inside especially ifyou have a flexible tip. Then work the door lock and see if it helps. If not you will have to pull the door panel off an dlube the linkage from inside the door.