There are tools to remove -- pull out -- fence posts easily, but they may or may not damage the post: Fence post puller

However, the fact that it may be hard to get a grip on a smooth shaft like that could make this difficult. Your best choice may be to unscrew the shaft, if you can, leave the point in the ground, and buy new posts.

I’d use a shovel. Those posts aren’t the highest quality. But they do work great for a temporary fence.

I think I mostly made it work. The problem was that I hammered the point too deep into the ground. Now I'm dealing with the final one being slightly too far over, so that's a whole nother thing.