Troika
Locate Delta 07
After the initial pair of Trandos here, you're going to come into a large room where more Trandos insist on taking up positions directly next to explosive barrels. Not the brightest scum around.... Anyway, this is going to be a good place to whip out your ACP Repeater, as it has decent accuracy at long range, and you'll be able to fire on the Trandos while 40 draws their fire, especially if you send him into the room ahead of you.
Soon enough, you'll come to a control room where you'll observer Sev getting the snot kicked out of him. You can't help him yet, so heal up and head down the ramp nearby. You'll come to a set of turrets overlooking a long corridor; feel free to use up any sniper ammo you have on them, as you'll be grabbing a box of it down the hall.
Shortly beyond the sniper rounds and bacta dispenser, you'll find another turret. Place your squaddie within, then help him staunch the flow of Trandos by shooting away with your sidearm pistol--there's no sense in wasting ammo on these guys when you have a bacta dispenser so close by. If anyone of the Trandos get up next to the turret, finish them off with a melee attack.
You'll come to the sealed door that blocks you from reaching Sev soon enough. Rather than breach it without the proper personnel, slice it open, then walk through guns blazing; again, this is a good time to whip out the ol' ACP Repeater. After placing Fixer in the snipe point near the door, sweep through the room and kill off every Trando you find. That'll learn ‘em for kicking Sev in the head.
Reviving Sev will spawn another appearance of a Trando Elite unit, but with a sniper in place, you should be able to take him down without having everyone die; feel free to join in with the sniping fun yourself, if you wish, but it's probably not necessary. Someone's going to take damage from his gun, but there's a bacta dispenser right here in the room with you, so it's a simple matter to heal up before proceeding to the end of the level.
Jailbreak
Locate Incapacitated Squadmate
Delta 62 is the last member of your team that you'll need to find. He's located in the ship's brig, which is under heavy guard, but that shouldn't matter now that you have your squad mostly assembled. To begin with, have Sev take up a sniping position behind the barricade at the start of the level, then move down the nearby hallway a bit until you trigger more Trando appearances. This is kind of a running theme in the game, if you haven't noticed: let your teammates snipe while you run forward and trigger an influx, then wait until all the enemies are dead before moving on and repeating the process. You'll be doing this a lot in the brig level, but thankfully there are plenty of sniping points for your killing pleasure. Not sure why a brig would be set up for close-quarters combat, but hey--if it works, it works.
Watch the side hallways for more Trandos as you proceed. You'll eventually come to an intersection where you can either disable a mine or blast through a barricade to proceed--blast the barricade, as attempting to take the mine out will leave you open to turret fire. After wending your way around the barricade, you'll find a bacta dispenser, as well as a side passage that'll let you get up behind the turrets, allowing you to take them down from close range without worrying about their fire.
After the turrets are down, place a soldier in the snipe spot below them and walk forward to trigger the predictable enemy barrage; the first set of foes is battle droids, while walking further down the hall will trigger a bunch of Trandos to bust through the viewport above. After both of them are dead, you'll be able to move up to the blast door that prevents you from accessing 62's cell. Before breaching through it, though, head up the path near the bacta dispenser to reach another viewpoint of the room beyond the door. Since there's sniper ammo up here, use whatever you have remaining to snipe out the turrets in the room before topping yourself off with the ammo box, then return to the door and slice through.
When the door is clear, be certain that your team doesn't charge through it; there's a mine on the far side. The safest thing to do here is to keep your team back, then crouch forward and click on the mine yourself; this will initiate the influx of Trandos into the area. When you hear them coming, immediately back up to the other side of the door. In their haste to follow you, the Trandos will trip the mine and kill themselves, or at least some of them. Heal yourself up before heading back in and killing the rest. (Alternately, you can slice the door, then return to the viewpoint from which you sniped the turrets and command one of your teammates to get the mine. Doing so will allow you to cover him with your sniper rifle and issue commands to both of your teammates.)
Locate The Elevator to the Bridge
When you've cleared out the brig, you'll be able to slice the console here and locate 62's cell, which is just around the corner from your location. Before you go to retrieve him, though, be sure there's a sniper in place across from the barricade near the console, as it'll soon be blown, leading to an assault of the droids. The battle droids will come to you, but the SBD's won't; they'll remain in the hallway leading to the exit from the level. You can probably kill the first two with a single EC grenade and the combined blaster fire of your squad, but the one nearest the exit is probably best just avoided; stun it with an EC grenade, then run past it to reach the exit.