Thanks Steve. There isn't a threaded bit to the leg in addition to the pin and hole fitting. I was hoping to see that when I had a closer look. The chair is screwed to the wall at the back so can't be turned around. The holes are 3cm apart and I'd have to drill 1cm up from the bottom one. I'm not going to do anything until I'm totally sure the company aren't going to help me but I just wondered if drilling there would cause a problem.