rare does not mean difficult. I have only ran into it about 6 to 10 times in the last 8 years of xp so its common enough but also rare.
you have to take the hard drive out of your computer and either put it into another system as a secondary drive which will require setting the jumpers on the drive, which the drive its self normally shows you how, or setting it to cable select.
If its sata then you just need to make sure your system boots off its normal drive.
or you need to pick up a usb drive kit from a local electronic shop and stick your drive in it for the task.. the drive kit needs to re the right type for your drive also, if your drive is IDE you need a ide usb ide kit, if its sata you need a sata one.
if you have friends that know how to do at least that I would ask them, if you feel comfortable doing it your self then go ahead.