There are a few things you can try to remove the dent from your leather boots. To start, try warming up the area around the dent with a hairdryer set to low heat. Then, carefully push the dent out from the inside using your fingers. If that doesn't work, try using a can of compressed air to blow the dent out. If all else fails, you can try using a leather repair kit to fill in the dent and make it less noticeable.