A quick and ready effort.
This is a simple use of the Clone tool. It's in the Toolbox and looks like a rubber stamp. If necessary, enlarge the image then click on the Clone Tool. I selected a brush size of 7 then you need to choose an area of skin which is similar to the area you want to cover. With your curser over the skin to be copied hit the Alt key. Move your curser to the snotty area and click. Keep going until you are happy with the result. Don't forget to use the Edit/Step back if you make an error. HTH.