Depending on the seat that you have, there are some tricks to make it easier to remove. They all begin with inserting your key into the right side cover.
Next, when I had the stock seat (06 Std Roc), I would put my fist into the middle of the seat and press down slightly, then turn the key with my other hand. I was rewarded with a click indicating that the seat latch had released.
I have since changed seats to the new dual tour with driver backrest. The procedure changed slightly. Now I stand on the left side of the bike, reach under the left side of the passenger seat and pull the ring that is there. This releases the back seat. Then I repeat the procedure above to remove the seat.
Enjoy the new ride...