aldocella,
Here's a method that seems to work most of the time. Remove the clutch actuator cover, the one over your drive sprocket. Protruding from the center of the sprocket should be a steel pin. (Behind thet pin there should be a ball bearing.) Give that pin a good rap with a plastic headed hammer or use a block of wood to protect it and use any hammer. It might take several good whacks but if the clutch pads are stuck this might free them. Some have had luck with tapping on the other side of the clutch but you don't want to beat it to death; just a couple of solid hits should do it. If you have the right side cover removed, move the clutch arm inward with your hand and see if you can see movement of the clutch pressure plate. Give this a try and get back to us with the results. There are other things to try but lets start with the simple things first.
Tom