Now there's two ways to solve the sliding tongue problem, you can either slit the tongue and put the laces through the slit or sew on a tab to put the laces through. First I'll show the slit method. Here I moved the initial marks to the outside and drew marks to the inside to show where to make the slit. Starting from the top use a sharp xacto knife, utility knife, etc and cut through the leather from the top of the mark to the bottom.