You can also need to use a small screwdriver to pick open the cap of the screws, the upper and lower two. I didn't take a picture of it before, but replaced it with a picture of it after I fixed it.
Unscrew the screws to disassemble the lock body windows can be opened, can not be unscrewed the key is the lock mold groove left wear and tear is not able to slide smoothly, here use a pencil, sharpen a little bit of powder coated as a lubricant, and then assembled to try to go back to run smoothly.