- Talk to everyone in city
- Go to the pyramid
- At the intersection, go right
- Push B to open door
- This part is pretty straightforward with the switches
- Kill the boss
- Pick up the item
- Cutscene, you're back at the entrance of the pyramid
- Get back to the city
- Talk to everyone until the same line gets repeated
- Now go right at the intersection from coming down from the city, but this time, do not go to the pyramid at the second intersection, instead choose the other way
- Now you are being let into this part of the game
- Talk to everyone
- Get back to the pyramid, but now go LEFT
...
I don't think you need more than this, I'm working on beating this game.