Destroy the Bridge
After the second dispenser goes down, you'll finally have the ability to place a charge on the bridge, which promptly fizzles and misfires. It doesn't seem like it would've done much damage, anyway, having been placed on the top of the span instead of at the foundation or the supports, but what do we know.
Anyway, after the charge fizzles out, you'll be commanded to fire a rocket at the fuel line underneath the bridge. To do so, you'll need to slice into the large door near the destroyed dispensers. Rather than forming up, though, start assuming that something big, say like a spider droid, will be coming out of the door when you slice through. You'll want two of your guys in the forward anti-armor positions on the bridge, with the third in the snipe spot back on the far side of the bridge. The AA position directly adjacent to the door will be too close to fire on the spider droid when it comes through, so leave it empty and move the soldier there over behind the dead Wookiee on the bridge.
After the spider droid comes through the door, it'll start wreaking havoc on one of your squaddies, but that's no big deal; you can just revive him later on. If you hide behind the little crate where the charge was supposed to be place, you'll be able to quickly command the two anti-armor soldiers to leave and re-enter their positions; this will let them fire much more quickly than they would if you just kept them in place the whole time. You can also pop your head out occasionally and snipe at the ocular cluster to wear it down further, or use your anti-armor shells on the beast if you know that there's another box around waiting to be picked up.
Detonate Fuel Line
When the spider's dead, move into the doorway, kill the droids blocking your path to the window, and fire a rocket at the highlighted spot underneath the bridge. Ka-boom!
The Wookiee Resistance
Advance To The End Of The Bridge
Now that the Separatists have been cut off from the main part of the Wookiee city, it's time to press on and rout their forces. This is really more of a job for infantry than commandos, if you ask us, but hey--you're already on the ground.
When you reach the tunnel again, a new path will be formed by Trandoshan explosives, so kill them, then follow their makeshift path until you reach a mine. This little area is going to be filled with Trandos, many of whom will enjoy the finer points of tossed Thermals, so you'll want to bring up your sniper rifle and take them down from a distance, if possible. Luckily, one of them will trip the second mine here, allowing you to proceed forward afterwards.
There's a charge spot on the far side of the room, but before you hit it, be sure that you've lain proximity mines on all of the explosives and healed up, because a minor Trando counterattack will form when you start the laying the explosives. They're just Trandos, though, so take them out before finishing the explosive-laying and moving on.
Behind Enemy Lines
Advance To Next Sector
Now that you've made it to the maintenance area underneath the bridge, you'll be able to bypass some of the concentrated enemy forces and proceed silently, without any bloodshed whatsoever. Hah.
Of course, as soon as you proceed down the hallway, more Trandos will pop in; apparently they've been waiting in the vents for you to appear. They'll first pop out in front of you; when they do, a snipe position will appear, so task one of your soldiers to it immediately. Soon thereafter, though, they'll start popping out from behind your position, as well. Although an anti-armor position appears that can cover these guys, we found it easiest to just leave the sniper in place with the other soldiers backing him up, then stand underneath the rear vent and melee the Trandos that pop out as they hit the ground. Easy as pie!
When you've reached the locked door around the corner, start slicing the console, but be ready to place a soldier in the anti-armor position that appears, as another ambush will be imminent. Kill the Trandos, heal up, then complete the slice to move on.
The underbridge in the next room is apparently being held by a single Wookiee, and he's doing a good job of it, by the look of things. Still, feel free to help him out by placing two soldiers in the sniper positions here, but hang back near the door, as three Trandos will come in behind you. When the coast is clear, set a soldier to slice the far terminal, which triggers the appearance of more Scav droids. When they've been sniped out, feel free to move on.
After the checkpoint, you'll come to a set of steps, at the top of which will be three Trandos. Killing them will trigger the appearance of a droideka in the same place, so concentrate your fire on it and take it out before moving your troops up and into the hallway. There are two anti-armor positions here, which is overkill when it comes to taking down the second droideka, but still, AA is AA. The real task here, though, is to round the corner and clear out all of the Trandos in the area; they'll chuck grenades at you when they spot you. Lots of grenades. The easiest way to deal with these guys is to instruct your teammates to stay back near the tree at the end of the corridor while you strafe out and start sniping at these guys from long range. If you strafe out far enough, you should see a pair of explosive barrels behind the tree that the grenadiers are set up in front of; if you shoot one of them, you'll probably be able to take down a few of the Trandos in one shot. There's some sniper ammo near the bacta dispensers here if you're running low.
When you're ready to move on, bring your squaddies up and take down the droideka before instructing one of them to grab the anti-armor position near its corpse, as there'll be more droidekas down the hallway to the left. They're easy enough to deal with, though, so dispatch the troops there, then head to the end of the level.