Once again, you'll have to hurry. Thankfully, these actions are very obvious. You will have to reach a few other icicles (#1). The last jump will lead you to a small platform. Be careful, though. It's VERY unstable (#2). You will have to make a second jump. Your next destination is a narrow ledge that's located on your left.
Start moving towards the right edge of the screen. You shouldn't have any major problems with the upcoming jumps. One of them will require you to reach an opposite ledge (#1). Once you're there, head on to the lower ledge. You should be able to reach a vertical pole from here (#2). Start moving upwards.
As you've probably suspected, you will have to make a jump towards the new ledge. Start moving towards the right side of the screen. Be careful, though. One of the platforms is VERY unstable (#1). You will have to move quickly (keep pressing the E key). Once you're at the end, make a single jump in order to reach the upper platform (#2). Keep moving forward.
I would recommend that you ready your guns. Once you leave the first cave complex, Lara is going to be attacked by a large group of enemy soldiers (#1). You will have to kill them all. Watch out for a guy standing by the heavy machine gun. He's located on your right. Don't forget to pick up ammunition and medkits along the way. Head on to the small ledge (#2). You should be able to reach some new platforms from here.
Keep moving forward. There's a well-known icon above you. Lara will have to make a double jump here in order to use the grapple. You must reach the roof of an opposite building (the one with the heavy machine gun). Climb up to the new platform and use the rope to slide down to the new ledge (#2).
There's a small slipway here (#1). You will have to use it in order to reach the second cave complex. Start moving forward. You should be able to reach an underground river very soon. Lara CAN'T end up in the water at any point, because it'll drain her energy almost instantly. You will have to wait for the ice floes to show up (#2). Start using them.
Some of the ice floes have longer gaps between them. In that case, I would recommend using nearby ledges (#1). Wait for the new objects to show up. Remember that you can't end up in the water. You should be able to reach a new corridor very soon (#2). It'll lead you to small stairs. Head on to the new cave.
You must be very careful, because Lara is going to be attacked by a new tiger very soon (#1). The fighting area is fairly small, so you should be using your machine gun in order to kill this animal quickly. You will find yourself inside a huge temple (#2). This is where you will solve the main puzzle of this mission.
Before you proceed to the main puzzle you'll have to reach the large statue. Ignore all of the surrounding platforms. You will have to use the grapple and start swinging on the rope (#1). Repeat these actions (there are three highlighted objects) in order to reach the new area. Be careful, though. There's a last tiger here (#2). You will have to kill it now. I would recommend shooting at the animal from the top of the small building.