Pour paint or varnish thinner into a plastic container.
Dip a scouring pad or soft brush into the thinner. Scrub the area of the skin that is affected by the varnish. Ensure that you repeatedly dip the scouring pad or brush into the thinner as you scrub the varnish from the surface of the skin.
Wash the skin with hot water and dish soap. Most dish soaps are good at cutting grease and will remove traces of the varnish and thinner better than hand soap. Ensure that you thoroughly wash the skin with the soap and hot water.
Apply a moisturizing hand lotion to prevent the skin from drying out due to the harsh nature of the thinner.