Kuwaq Yaku – Side Mission: Invasive Species (part 2)

Lara automatically draws her bow, but you'll need to step forward to hide in the tall grass. You can then decide if you want to switch weapons or use a stealthy approach to confront the first 4 bad guys ahead.

There are lots of places you can hide in this area, tin cans you can used for distraction or to make shrapnel grenades, ledges you can climb, and walls you can use for cover, etc. I'm sure you'll find your own way, but here's a stealthy approach that worked for me:

Move into the bushes on the right side of the path and gradually work your way forward...

...until Lara is hiding just behind the first enemy. Make sure he's unobserved (yellow in Survival Instinct) and press Melee for a stealth kill.

Sneak forward to the next clump of bushes, staying close to the right wall so the men don't notice you.

From here you can watch the next 3 enemies. The second man is workign on a generator. The third and fourth are talking off to the right. When the fourth man moves away to the left...

...you can use your bow to land a silent headshot on the one near the generator. (If you've unlocked the Warrior Skill Raposa's Threat, you'll see an enhanced targeting reticle for headshots. Even without this, you can still land a more headshot: Hold Aim (Right Mouse/Left Trigger), aim at the enemy's head, Zoom in by pressing Z/R3, hold the Fire button (Left Mouse/Right Trigger) briefly to charge your shot, then release Fire to shoot.

He dies without alerting the others, and you get a nice XP bonus for a stealth kill.

If you're quick, you can take out the third (right) and fourth (left) enemies using headshots before they can react. Otherwise wait here in the shrubbery until the guy on the left moves back toward the other man and away again.

You want to make sure the 3rd man is not being watched by the 4th (yellow in Survival Instinct).

Then take him out with a headshot the same way. (If Lara can't see him from behind the bush, press Left Shift/L3 to shoulder swap.)

When he's dead, quickly headshot the 4th guy before he notices what you've done.

Run around and loot the bodies before heading up the steps on the right toward the next area. You need to do this so the next group of enemies will spawn...

...but as soon as you spot them—and before they can spot Lara—return down the stairs and hide behind the storage box on the landing.

When he's dead, quickly headshot the 4th guy before he notices what you've done.

Shoot an arrow into the opposite wall near the top of the stairs.

This should alert one of the enemies, so he'll come to investigate.

Headshot him as well.