I bought 5 sonoff basics expecting them to come with holes in the pin locations but Sonoff have changed their products and now they come with solder pads instead of holes. I butchered one of them trying to remove the solder and thought wow, this isn't going to be fun. Then, wait.... I have a 3d printer and the smarts to make a jig that will allow me to use spring loaded probes to make the connections. This is what I came up with and was able to flash all my sonoffs to Tasmota.