This is also included in the Ghana traps video.
After clearing the first set of blades, follow the hall to another spinning blade trap.
Since you can't get the first carved block up the stairs, you'll need to find another. Turn away from the trap and scan the wall ahead. There's another dark brown movable block recessed into the wall.
Pull it out.
Then go behind it and push it through the blade trap as you did the previous one. Here pushing the block along the left wall seems to work best. Push it forward until both blades on the left side of the trap become stuck on the block, as shown above.
Then release the block, jump on top of it and jump down on the other side. Continue forward, staying to the left to avoid the other set of blades.
[Part 2 | Part 4 | Return to the Ghana Walkthrough]