The server room is well-guarded, but we can solve that with the power of friendship.

Your friends had no problem lifting you into the construction zone's hidden area - maybe this room has something flammable in it?

A matchbox should do the trick - you'll find it on the barrel on your right.

Using these on the oil in the server room is sure to be a blast!

With the room cleared, you can now 'use' the 'big thing' in the corner of the room.

This will interfere with the servers, so switching off the computer now will make it forget that the facility is supposed to be locked down.

Yanking out the cable on the far right side of the computer room should do it, but it's impossible to touch without some kind of protection.