The clips that secure the front cover are tricky to release. During the removal procedure, you may have to wiggle and bend the plastic to get the clips to release properly.

Pull the front cover away from the lens to release the clips along the front edge and slide the viewfinder out of its cutout.

You'll hear a "click" and the front cover will be able to move freely.

During reassembly, align the viewfinder cutout over the viewfinder lens before pressing the front cover into place and re-engaging the clips.