1. Disconnect the wire from the negative terminal of the battery.
2. Remove the front door trim (see "Removal and installation the front door trim").
3. Peel off the moisture-proof film from the inner door panel.
4. Remove the lock switch and the outside door handle (see "Replacing the outside handle and front door lock switch").
5. Unscrew the bottom...
6. ...and the upper nuts securing the rear door glass guide.
7. Remove the rear door glass guide through the service window.
8. Loosen the screw securing the outside handle base, slide the handle base forward and remove it from the door panel.
9. Remove the three screws securing the lock...
10. ...and bring the lock into the opening of the technological window.
11. Pull out the retainer and disconnect the wiring harness connector from the lock.
12. Remove the door lock button rod seal from the door opening...
13. ...and remove the door lock assembly with the base of the outer handle through the service window.
14. Press the latch...
15. ...and lift the locking plate of the outer handle rod of the lock.
HELPFUL TIP: If you are removing the lock for purposes other than replacement, measure the amount of protrusion of the outer handle rod thread from under the lock retaining plate so that the rod is set in the same position during reassembly.
16. Disconnect the lock switch rod from the lever and remove the lock.
17. Install the front door lock in the reverse order of removal.
NOTE: After installing the outside handle, make sure that the handle releases the lock clearly. If not, adjust the outside handle rod by moving its threaded end in the lock retainer.
(The article was borrowed from the website «CHEVYMAN»)