I used to be a full time custom knifemaker. Now and then I would get a knife sent back with the tip broken off. Almost no one ever told the truth about how it happened. Funny.
You can reshape the tip, but you will probably end up with a tip that is too thick to sharpen at the same angle as the rest of the blade, and maybe to thick to take a good edge at all. If that is the case, the sides of the tip will need to be reground, and I would recommend finding a knifemaker or bladesmith to do it. As Tom pointed out, you have to be careful not to heat the blade beyond a certain point or you will loose the temper. Most knifemakers are good guys and will feel you pain and do it for free.