How do I sneak past the guards in the west hallway?

Hint 1 of 5:

There's a suitable hiding place for you in the hallway.

Hint 2 of 5:

All you have to do is walk in.

Hint 3 of 5:

Make sure to do so when they are facing away from Alex.

Hint 4 of 5:

Walk into the alcove in the middle of the hallway.