There is a piece of reinforcing steel in the door that goes from top to bottom. And that lock has tabs above and below that might be resistance welded to it.
Its possible the steel rail might be removeable by taking out the door and pulling out the rail from the bottom, but I have my doubts. The door frame is probably glued together.
The lock might also be glued in. I have seen that with rollers in Vinyl doors. Even if it is, the new lock will have tabs above and below that have to be recessed into the frame.
I would try cutting the PVC away from the top and bottom of the lock with utility knife as neatly and carefully as possible. About 1/4" x 1/4"
Hopefully you will find screws there, covered up. Or the lock will just drop out once the tabs are uncovered.
They install the lock this way to force you to buy a whole new door when the lock breaks.