The Jedi Super slam is when you double jump then slam into the ground (Tap A twice to do a double jump then hit at the top of the jump to perform the slam). Do this when there are 5 people underneath you to receive this. This is easily done in Chapter 2 of Episode 1, destroy all of the pieces of the broken down Transport. There will be a hole underneath one of the pieces with a mini-kit in it, fall in the hole. When you are in the hole wait for 5 enemies to surround the hole. Double jump out of the hole and use the Jedi Super Slam on them and you should get it.