Hey Duckkiller there are several ways to accomplish what you are looking to do. Here is what I have found works well for me.
Get the Ozi Explorer software for your computer. This is a mapping and waypoint management software that is fairly low cost.
Connect the Garmin 76 to the pc using the interface cable. Download the waypoints and name the file.
Now go to Humminbird register your unit and Download Humminbird PC.
Use Humminbird PC to upload the file you created in Ozi Explorer.
Same this file from Humminbird PC to A SD CARD.
Simply put the SD card in the 587 and the waypoints will update automatically.
Custom naming of the points is easy from either the Ozi or Humminbird software.
If this all sounds like Greek make a trip to Columbus and I will demonstrate it for you.