Fastest and easiest way would probably be to printout 1 doz sterograms (colour ones work just fine in black and white). Practise on them a couple of times a day. Look at them by looking throught the paper. After working on this a couple of times a day (give yourself breaks) for a day or two... you'll probably notice how it feels when you are doing it right. Then just check once in a while for a week or two to be sure you haven't slipped into convering again.

Alex