The first few challenges are pretty straightforward. Go up the stairs.
You'll reach a blockage. Just climb over.
Jump on the ledge and continue (child's play).
At the next block, crouch through the opening in the rocks. Go forward. Lara will grab onto the ledge. Go sideways until you reach the platform, and let go (Ctrl key).
From there, go down further until you get to the bottom of the pit. You'll notice a tunnel. Go through it!
Climb back up.
Continue until you reach the chamber with the giant Kraken.
Go to the right.
Use the ledges to get over the pit.
You'll reach some pillars on which you can grab onto.
Jump from one to the other, until you reach the last one.
Then get to about the same level with the ledge on the other side and jump.
Go sideways. WATCH OUT. In the moment you go on the platform, time will slow down and you must jump so that you grab the pillar.
Get on the bridge.
You must first separate the two sides of the bridge from the center. Youíll do this by getting to the chambers to the side, and activating the lever.
In the one on the right you must first get in a position to grapple the ring, and pull it, to crush the Krakenís tentacle.
To reach it use the ledge on the wall, and the horizontal pillar.
Grapple and pull (E key). The bridge will now retract.
In the other room it's as simple as grappling and pulling the wheel. Then just engage the lever.
Go to the center lever and activate it. The chandelier will rise. Using the Z key shoot the loosened rings on each side of the chain. It will crush the Kraken.
Grapple and go down to where the Kracken was. Pull the lever.
Proceed and climb on the wall. Use the directional keys to go in the direction of the grips.
Go forward. Don't forget to balance.