The light in my shower room is lame and annoying, I'd like to change it for one of those lights that looks a bit like half a massive glowing smartie stuck to the ceiling. Something like: http://www.lightingstyles.co.uk/Bathroom_Ceiling_Light_fittings.htm?ob=LP

I'm assuming that it's just a case of unscrewing the current fixing and rewiring it, then screwing it to the ceiling? (After shutting down the lighting circuit from the fusebox) I've not really mucked about with lights too much, anyone had any experience doing this?