How do I get here

Hint 1 of 4:

The power plant is where Ferris Collett works.

Hint 2 of 4:

Did you visit the murder scene and get the I.D key ring ?

Hint 3 of 4:

Open the safe back at Terraform after the murder

Hint 4 of 4:

LOOK inside. Also look at display (lower right) in outer office.