Without getting into two much detail, there are two primary techniques to reposition an IOL. One uses a laser (different that Lasik laser) and another is manual manipulation.
The natural lens within the eye is very much like a grape. It has a strong outer "skin" and a soft pulpy center. During the surgery the doctor creates a small hole in the front of the outer skin and using ultrasonic energy and vacuum breaks up the pulpy center and removes the pieces. This leaves most of the outer skin intact. This "capsular bag" is where the IOL is positioned. Tiny tension haptics that look like curved whiskers from the IOL extend out inside the capsular bag and this slight tension helps center the IOL.
Manual manipulation is just what it sounds like. The surgeon would enter the eye through very small incisions (probably using the ones used for the initial surgery) and using a surgical tool rotates the IOL into position.
The laser uses release of the internal tensions within the eye to reposition the IOL. Depending upon how and why the IOL is misaligned, it may be possible to use an ngYAG laser to create a hole in the capsular bag. A properly placed hole will change the internal stresses and shift the IOL in the desired direction.
It is also possible that the lens needs to be removed and replaced, but this is rather rare for a decentration issue.
What method is best will be determined by your surgeon.