You don't say what make/model it is but although laptops are quite tricky to get at the internals they are generally not as bad as you aremaking out. The problem is very common and can be an easy repair once you get at the socket.
Its a common fault and I have replaced the power socket on several Dell laptops now and a Toshiba (for friends and family). I had no trouble getting replacement parts; sourced them all from e-bay. In all cases I had schematics that I downloaded from the manufacturers web sites. I also drew a picture of the laptop insides and taped the screws, dismantled components down to the drawing so that they went back in the same place/orientation. I strongly suggest you do the same, especially if you can't get a schematic.
It is not an easy task and you will need a soldering iron designed for the job (very fine tip). A general purpose one with a fat spade tip will just make a mess. If your a novice with a soldering iron I don't think that you will stand much chance but if the laptop is written off then there is nothing to lose. The key is to be quick so you don't heat up the surrounding components and board too much and use a desoldering pump for the extraction of the duff power socket.