Magellan Mapsend Direct Route US and Canada Map Making

A couple years ago I had bought some info from someone on ebay that would allow you to change some parameters in the software so as to make large maps from The Direct route big enough to make like 4 large maps of the COMPLETE United States and put them on a 2 gig card , thus having no need for the software any longer. The catch was once you make them the software asks the serial number of the handheld unit you were to use them on. So, once you put the maps on the card the only unit that would recognize them would be the unit whose serial number you put in when you originally made the maps. My problem is that my unit went bad and magellan sent me a reconditioned unit in trade and it worked only for a short while and now they don’t service them. I have purchased a used one and I have bought the software again but have lost the info on how to make the large maps by changing parameters. Does anyone know how to do this?:bow: I have a magellan explorist 500.