Ok, this started as simply explaining my troubles with the glitch but I decided to give some hints and a mini walkthrough. If you beat the DLC on Unleashed, but don't get the cheevo, simply play it again on unleashed on a new save file. This fixed my problem. On to my tips.
When you start make your way up the hill slashing enemies. There really is only alot of average enemies with a few laser snipers. I'd like to point out that jedi mind trick would be awesome for this if it wasn't horribly glitched. So just keep slashing away.
After the log area you will come into a confrontation with those cute little ewoks. When playing I would dash around grappling (X+Y) them Just like the average troops though anything will knock em' down. The next few encounters you can simply run through so just dash(LB) around the enemies until you reach Han and Chewie.
What I did for this battle was to jump around behind him/under his legs and keep slashing away with some force repulse to get rid of the ewoks. Chewie will often back himself into a corner making my strategy easier.
When you first enter the base keep moving and grapple everybody. I found this the easiest to handle this room because of that laser watching the room.
For the next big open area, I found this part hard to give any tips except that using the force makes part pretty easy.
Now for the boss,
Part 1: Just be offensive keep hitting the boss( Im not gonna spoil this ;) ) Don't give it the chance to hit you.
Part 2: Just keep throwing your sabers at the turrets you'll get through it easily.
Part 3: Keep being offensive. When the boss jumps up on the ledges throw your saber at the boss and dodge his oncoming attacks. Rinse and repeat
Part 4: This is basically the same as part 3 but harder. I hope you saved your unleashed power (you should have), because that will make this cake(not a lie). This part starts with the boss jumping onto a ledge. When the boss jumps back down activate the unleashed power(tap LS and RS at the same time) and slash away non-stop until you WIN!!!!
Hope this helps.