First, you run to the AT-ATs you're supposed to destroy/disable (use
the y button if you don't know/they are the bright yellow) when you
find one, run under it and push c-up (if you do it right, your person
will shoot up a black cord)then you push up on the control stick until
you go to 1st person view automatically (you can't see yourself) your
person will pull out a light saber. slash the AT-AT with it and then
press b. you should see little red crosshairs. aim it at the 
hole. repeat this with the other one but be fast (you're on a short
time limit, which i found out the hard way) when you've done that,
head over to the tower(look at radar) and go to the blue rebel sign.
then you'll get on some lizards. go to where the radar shows you to go
and kill as many storm troopers as you can(note: you get a laser
machine gun while on the lizard) once you get to your destination you
will get off the lizard. look for a stationed machine gun and press c
to use it(it would be a good idea to kill the troopers first) and
destroy all 3 of the
AT-STs(there's no auto-aim so it'll be a bit hard to aim. once you've
done that, your person will automatically get in an x-wing(there will
be a short little movie clip) now alls you have to do is destroy the
tie-bombers(they are in bright yellow) (by the way,if you didn't
already know, all mission requirements are in bright yellow) it's not
very easy(it took me a couple of trys to beat them)go for all the
clusters, don't take your time.