Unfortunately, it is copyrighted software. You can try calling Magellan on their toll free number, but they do not have the best track record for tech support. Their website does NOT have this for download. The software should be on the TOOLS CD that usually comes with the unit. The software you want is called: "Magellan POI File Editor".
There are several versions of this software and Magellan told me they were unique to each GPS. I have found that this is not necessarily so.