All you have to do is heat the point and the pin at the same time (by placing the tip "wedged" in between) and feed solder in between the pin and the point. I don't see how the length of the pin makes a difference -- it could be a foot long if you wanted, solder flows toward heat.
If you ever solder a header pin, and it VISIBLY looks ok, but the pin moves when you push on it, you need to clean the area, use a little flux, make sure you are using the right solder (pc rosin core works great), and that the iron is hot enough (if it doesn't smoke a little while you are soldering it is not hot enough). Your solder job should look like liquid mercury, nice and shiny!
Hey, but what do I know, I have only modded around 200 consoles, 99% of them using the header pin method
