You need to remove the whole cluster surround (ie the entire black plastic bit that goes all the way past the A/C vents - it's only a couple of screws above the cluster & the rest are all push-in clips).

Once it's out, you rotate the retainer on the rear of the headlight switch to release it, and it drops out of the surround.

These rarely give trouble - if at all. I've never known anyone who needed to replace it. More likely culprits for faults are the headlight relays in the underbonnet fuse box, and the BCM - which controls the auto lights-off function (if you leave them on, it cuts power to them when you open the drivers door).