Lean the bottom of the bottle against the wall or tree, keep the bottle perpendicular to the wall or tree, and hit the bottom of the bottle evenly and forcefully at the bottleneck with your hand, and the cork will be slowly pushed out.

If there are no walls and trees, you can also hit the bottom of the bottle with your knees or soles.

Once the cork is partially ejected, it can be pulled out by hand or pliers.