NOTE: THIS GUIDE ASSUMES THAT YOU HAVE DESTINATIONS COMPLETELY WORKING WITHOUT VR. IF YOU ARE HAVING TROUBLE WITH THAT PLEASE USE ANOTHER GUIDE.

First of all, open the console with the "~" key (usually next to the 1.)

Now you want to enter these commands into the console. Make sure you enter them seperately and in order.

• cl_mouselook 0
  
• bind downarrow +lookdown
  
• bind uparrow +lookup

That's it! By pressing the up and down arrows, you should be able to look up and down.
You can bind them to other keys by replacing "downarrow" and "uparrow" with whatever key you want. Sadly, I don't think there's any way to bind it to mouse movement.

Even though the game doesn't have mouse movement, it thinks it does. So "cl_mouselook 0" lets the game know that it doesn't use mouse movement.

Now the game lets you bind keys to look around, so when you press a key you look a certain direction. That's what "bind downarrow +lookdown" and "bind uparrow +lookup" do.

If you just typed "+lookup" or "+lookdown" you would just infinitely look up or down. (If you do this replace the + with a - to stop.)