Most older models were designed to be either a PH or LH opening door and were not usually reversible. That mainly came about in the 70's.
On models that were, not only were there hinge screw hole in the opposite of the cabinet like Steve suggested but also on the door itself to mount the handle on the opposite side. If your model has a mechanical latch, it definitely is not reversible.
You can read how it is done on some makes of [i]modern[/i] refrigerators at the following link: