Okay, I'm going to show you how an edge sander works. Okay it's a rather large tool, it's a disk sander more or less the disk spins around on here, you can put a big heavy grit on it and then go down to a finer grit, but it has a plate that moves around on here so that you can get right up to the edge of the your 90 degree here. So you just get it in place, make sure you have a hold of it, lift it up a little bit so it's not in the wood. That prepares your edge so you don't meet up with your drum sander here. It's a lot better than getting down on your hands and knees and just using an orbital or a belt sander. I highly recommend this to just take off the stain and you go with it.