It means, if you're out of warranty, ie. 12 months + old drive failures aren't covered.
Therefore, take the 360 apart, take the dvd rom out, dissassemble it following a guide, on the laser there are two pots (potentiometers) these regulate the voltage that gets to the laser. Over time lasers weaken, which is nothing new, to compensate for this you have to adjust the pot so there is less resistance and more voltage, giving a brighter beam and making it easier for the drive to pick up the pits.
That's all there is to it.