Go to any space map. Go into a ship in the docking bay. Keep landing and taking off until you are at the forcefield. Take off and land very quickly. You will land with the back part of your ship inside the forcefield, but the front outside. Get out of your ship. You will now be walking on a ledge on the capital ship. You can shoot the engines and the capitol ship itself, but it will barely do any damage. You will not die unless you run off the ledge; then you will keep on falling for a very long time before dying.

Play in the space Yavin map as the Empire. Get in a TIE Interceptor and take off. Keep landing and taking off until you are in space and have landed. Get out and walk around. You should be on the ledge of the Star Destroyer. You will not die and your ship will stay there. If you are a marine, you can use the rocket launcher to destroy enemy ships. If you fall off, you will keep falling and will not die. You must kill yourself in order to do it again. Note: This may require a few attempts.