Now you want to follow this:
>>1271369 Except that you should hit colorize button on the first layer(background or layer0) to get everything the same color.(I usually darken it 1, and add a little saturation) Then proceed to the multiply layer after that.
Choose a brown you like, and set the brush to between 75-85, and paint your selection. Try this twice, if the color doesn't do it for you. Then look at what you have done.
If it looks bad just go back a step or two, and play around with it.
