Fairly simple. Used the polygonal lasso tool with a 1 px feather to outline the gnome. Dragged the gnome to the bathroom canvas. Used free transform, polar coordinants to bend urine stream. Adjusted hue/saturation to the color of pee.
step 2 of 2
Duplicated the gnome layer and removed all contrast and then changed opacity to make transparent for a shadow. Cropped to put the focus on the gnome.