Starting with the top clip is easier, as it's easier to get a grip of the faceplate once it pops out a little bit. Use a spudger to prevent it from popping back in, but holding it in place with your fingernail is also possible.

Pushing slightly off-angle (as indicated by the arrows) can be much easier due to the internal shape of the clips, so it is recommended to do it this way to prevent damaging the plastic.