Today we’re installing an oak threshold and then we’re mounting an aluminum, it’s called a butt threshold- it butts up against the door. To prevent water from going in. and the reason we’re doing the oak board is because of the slant on the slab. And once you have your board cut, you just want to take your scrap to hit against the edge. Rotate back and forth from side to side to prevent the edges from getting dinged up. And once you have that installed, you just want to get your aluminum piece, and this is going to go in this same area, the same width as right there. So you just want to measure that and lay it out on here and cut it with a hacksaw or a pair of tinsnips will cut this too- you just have to be careful not to bend up the edge real bad. And that’s how you would install a back door threshold.