Climb the Tower
Break camp and use your Climbing Arrows on the walls around the area. You need to have at least one Arrow in the wooden spot beside camp and another on a different wall across the way. Climb your Arrows and pan the camera around until you see a third soft, wooden spot while Lara is standing on top of her Arrow.
Shoot another Climbing Arrow from your current position onto that wall, and then jump over to it.
Jump from that Arrow onto a few handholds farther along, and climb to a new platform. Get to the top and use Climb Arrows yet again to Keep ascending. Use your Bow and Rope to swing across the gap above, and climb an ice wall until you reach more handholds. Shift around the left side of the building, and continue your climb.
Grapple across a gap, and then do this a second time as you come into a larger chamber. Lara ends up on a rockface. Grab hold of it with your Axes and shift to the left side of the rocks. Pull yourself up and survey the platform while you get your bearings.
Use more Climbing Arrows to get higher in the room, and leap onto a ledge to Lara’s left (as she’s standing on her Arrows). Vault toward your objective, use a swinging Rope, and land on an ice wall that gets you almost to the top of the tower.
Use Climbing Arrows to get a bit higher on that platform, and grab the handholds at the top. Shift left until you can slip in through a window. Grapple across the next gap, climb the rest of the tower, and stop when you get to the Broken Spire Base Camp!
Reach the Top of the Tower
Look for the ice wall that is close to the camp and use that to reach a long series of handholds. Climb as far as you can before siege damage causes the handholds to break away from the building. Jump to the spot to your left to continue up, and watch a scene as Lara gets to the top.
Shimmy along the walkway as you advance. You need to jump over to an ice wall, climb a short distance, and then continue toward the very top of the tower as best you can. More of the ice and stone break away, but you have to hold on.
Jump up and climb the remainder of the ice and handholds. To reach the last ledge, jump and use your grapple. Lara is grabbed by one of the Deathless, but gets a hand free to unholster her Pistol. Fire into the guy’s face as many times as you can. He’ll fall. You’ll live.
Lara gets over the edge in another scene, and you regain control soon after.