Here is my video guide to all three starlight upgrades, this is the second one.
1. Start by helping the ghost on the bridge at the fields, by getting his ID card next to the convenience store.
2. Go to reality folding drives (north end of the map on the big bridge) and go to the save point at the big building/door.
3. There is stairs with like 5 steps that just goes up and over a pipe. Go to this area with the three purple doors.
4. Open the only one you cannot see right away, on your right.
5. Open the locker, with Ezra's code, to retrieve the Pyramid Starlight Upgrade.