I renewed my license yesterday and it was very easy. The hardest part is standing in line. 1) to find the location just turn left at the lights (coming from Ajijic) and take the first right after passing the Permanent Market (there will be a green Chaps Ice Cream shop on the corner). Drive almost to the end of the street (you will probably see a lineup going into a white building). 2)Join the end of the line. If you are unsure and you don't see any expats in line to ask, just ask someone "placa?". That is how you say "plate" in Spanish. 3) when you get to the counter just hand over the paper receipt from last year and the laminated card that is good for 4 years. They may tell you that there are unpaid speeding tickets that must be paid before you can renew. You can pay with a Mexican credit card or cash. They will return your card and the receipt for this year. That's all it takes.