That is a good question. I had a 1100 magna the same year and I had a time finding that out. It is very simple once you figure it out. You just take your key that will turn the helmet holder on the side of the bike. You turn the key in the helmet holder until it opens and then work the seat and it will just pop right off. Hope this helps.
Easy - put the ignition key in the helmet lock (located on the left side under the rear seat) and unlock it. Then pull out the seat release lever that's in the helmet lock while lifting on the rear seat. It should come right up.