This impromptu video shows removing the GBA's 0603 SMD power LED with a soldering iron only, and with hot air. I had some trouble figuring out how to orient the LED, so unfortunately I won't be much help there. After some trial and error and a few bloopers, I was able to get the new LED working.
WEP 858D (110V) Hot Air Rework Soldering Station - http://amzn.to/1y4czLa
WEP 858D (110V) Hot Air Rework Soldering Station - http://amzn.to/1y4czLa