Just did a test on a 2.5 to big ide hard drive converter. I was able to desolder the header with a desoldering braid.
For those of you trying this. Use a good clean tip on the iron, and a clean braid, don't be stingy and re-use areas or the braid.
The worst thing you can do is lift one of the threads or grommets embedded in the motherboard. This happens if you have a cheap soldering iron with inconsistent heat on the tip or if you leave the tip in too long.
Going to try to remove the A1200 header, got to get a new cable and header at a computer show.
Will post shots in the tutorial area.
I will say, those of you that want to solder your own Mini-Mig are in for some nail bitting, nerve wracking time unless you work in a surface mount equipped electronics/ machine shop.