We are replacing the bottom threshold in a backdoor today. And as you can see, some of the area has been chipped off. They have poured concrete which slants inward, which eventually caused enough water to come in to rot out the kitchen cabinet. And what you want to do is you want to make sure to chip off at least this top little layer. You don’t have to pull it all the way back to the other side at the threshold because we’re going to install an oak board that will slant outward so that when it rains, the water will drain outward. Get yourself a large, cold steel chisel and you just want to chip away at the concrete until you get the top little edge off and you can shim up this side of the threshold. And you also want to- after you’ve chipped or before you have chipped all of the concrete along the edge on this one, you want to remove the old threshold. This should be fairly easily done. This is just aluminum on concrete. It might be screwed in, it might be bolted in, it might not be either. So you want to get a pry bar, pry up on it until you get it all the way out. And then, you just need to scrape all this nasty stuff out from underneath it and take out all the old floor tile and what have you. This is how you would prep the area to install a new door threshold.