Hi all, DIY noob here. We have ugly cracks between our stairs and the wall that we would like to cover / fix. It’s at an angle and I have no idea what to use or how to apply it to have a decent result. We bought some quick dry filler and have a ‘flat spatula’ ( sorry not sure of the terms to apply it ! But I don’t know if we should first remove the broken bits that are on the crack. Or cover it up with the filler. And then just try to flatten it with the spatula ? Any advice will be greatly appreciated !