What do I do in the pyramid

Hint 1 of 21:

You need to know how to use the yellow crystal.

Hint 2 of 21:

Find the dot that looks like it's near Cairo and teleport there.

Hint 3 of 21:

Try that lever on the left wall.

Hint 4 of 21:

Stairs open up when you pull it. Go down them.

Hint 5 of 21:

There's the same old sarcophagus chamber.

Hint 6 of 21:

Go back up and look at the base. Look familiar?

Hint 7 of 21:

It's the bottom part of the device!