I've opened up a Buffalo boiler before and it is tricky to get the feet off without marking them. The screw is hidden inside the feet and the bottom of the foot forms a cap enclosing the screws. The seal line you need to get through is almost imperceptible and I spent some time hacking away at mine in the wrong place.
BTW, if you encounter the dreaded Buffalo boil cut out there is a very simple fix, if you are prepared to monitor/manage the temperature yourself. When you do open it up, just loosen the screw that holds the temperature probe against the base (silver torpedo shaped thing on a curly wire) and move it away from the base. Doing this means I can happily maintain a rolling boil in mine but I do need to keep an eye on the temperature myself if I am heating strike water for instance and switch it off when it is hot enough.
