First choose Corasuant and pick any session but choose Clone Wars for ERA. Choose Republic and kill people until you have enough points for a jet trooper. Choose the library command post (the one with the bookcases) and start as jet trooper. Go down the hallway and go up the right stairs. Go between the square corner and use your jet pack to go up the wall. You'll go through the ceiling and if your careful enough you'll be walking on top of the jedi temple! You can go to a lot of good sniper spots. It's a pretty cool glitch you can even do online. So try it and kill some suckers!