Do not remove the bottom plate while film is still loaded if you want to preserve the shots. Even if the plate itself is not directly over the film, the film advance mechanism is linked to parts that interact with the film path, and opening the camera to inspect a jam can let light reach the film.

Safest approach: remove the film first. Try rewinding the roll normally; the advance lever being stuck does not always prevent rewind. If the film will not rewind, use a completely dark room or a changing bag to remove it without exposing it.

Once the film is out, you can inspect the camera more safely. If the roll contains important images, avoid opening the camera in normal light.