Make a click on the right mouse’s button on the layer and select the Create Layer option as it is shown below:



Select the separate layer containing the shadow and apply the Eraser Tool (E) to erase the upper edges and the lateral shadow’s parts.



Create again a new layer and use on it the Polygonal Lasso Tool (L) to represent a marking, looking like a stripe created when tearing off the sticky band and then select the Burn Tool (O) to paint the marking with the color #999999



Apply for this layer the Blending Options>Drop Shadow.



Apply the layers’ parameters for the layer in case:



We should get the same result as this one: