Start by placing your tenderloin on your cutting board with the head on your non dominant side. Place the tip of a sharp boning knife under a section of silver skin just below the surface. Tilt the knife blade so it is just above horizontal, while holding the silver skin tight, slide the knife along the silver skin till it ends. Turn back towards the head, while holding the silver skin strip tight, make the same movement all the way up to the top of the head. Repeat this procedure till you have removed all the silver skin.