This is a tactic to use when you are on Hoth, playing as the Rebels.
You can only do this when you play as Luke Skywalker.
Get near [one of] the
AT-AT's, and press A (on Xbox) 4 times. You should be able to get onto the top of the AT-AT
NOW...use your lightsaber, to whack at the AT-AT
. You'll VERY QUICKLY be able to do some MASSIVE/QUICK damage.
(It is SUPRISINGLY effective!!!