Here is the easy way:
1) FF = OFF
2) ELITE difficulty, and Auto-Targeting must be off.
3) Go to the geonosis stage, max out population cap on both sides, set AI numbers to small, 6-10.
4) Play as CIS, aim against AT-TE, under the head for the critical. You can get a Demolition with a few nice hits. Now go do some nice pistol kills and what not(you can change class), wait for 1.5 minute or two, then suicide. You might also want to go CP balancing instead if you wish.
5) Don't worry if AT-TE is destroyed, it will spawn back soon. You might want to switch to Republic once in a while to rebalance the CPs and what not, or to "move things around" a bit, or to get some kills for other medals while you wait out your "grace period".