It's not something you're going to be able to do on your own. Taking the motherboard out pretty much means a complete dissasembly of the system. There are probably some instructions on how to do it, but most I've seen don't go for a complete mobo removal, just enough to get to certain parts which are prone to failure. To take the motherboard out, you pretty much have to strip the machine completely. Not really that bad, but would be daunting for someone who's never tried it.
If you're lucky, it's just the center prong of the recepticle. If you're even luckier, it can be soldered with only the keyboard removed. If the back of the recepticle is covered, then the only alternative is to completely disassemble the machine and replace the recepticle. For that, you need a soldering iron, as well a solder sucker. Without the latter, it's going to be difficult to get the recepticle out.
Parts are pretty cheap, I picked up recepticle on ebay for $10 or so. Probably take 30 minutes for someone who knows what they're doing. But it probably wouldn't be cheap.