Go to Polygon sub-object mode and select the polygons highlighted in the image. Once more, make sure no backfacing polys were selected.
Extrude the selected polygons with a Height of -1.0, then Inset them 2.0 units.
Bevel the polygons (Height: 0.4; Outline Amount: -0.4) and then Inset them (Inset Amount: 0.6). Bevel them one more time (Height: 0.6; Outline Amount: -0.6).
We have just opened our tutorial directory! Feel free to submit tutorials hosted on your website or other online tutorials that you think are worth mentioning.