i'm confirming capnkelly's comment. it's common that the clips pops off the latch drive rod. it requires removing the armrest and trim panel, roll the window up and try to move the actuator to the latch with a pocket screwdriver. it's a blind operation. while your there clean out the latch and relube and replace the clips.

Does the button push in on the outside door handle? If not, then the locking mechanism is seized and will need to be replaced. Or, there is a connecting rod between the latch and the door handles that WILL come off. I have had to replace both of the above. Its tricky, but it can be done in about 30 minutes.