How to model aTelephone case in SolidWorks
Using Extrude command, extrude the side view.
Now add necessary fillets and 'Shell' the feature upto 2 mm and remove the bottom face.
On a plane constructed approx 40 mm above the top plane, sketch the buttons and "Cut Extrude" them all the way into the model.
Now Sketch and Cut the speaker holes from the same plane.
Lastly, using hole wizard make the speaker holes and pattern them along a circle.
Render the model and. enjoy...