Martyn997 :
THIS CASE http://ecx.images-amazon.com/images/I/71n%2BoCOK7PL._SL1088_.jpg
not sure about this particular case but in general you remove the side panels and look for plastic clips, try to figure out whats holding it. sometimes you have to remove the top panel too. look and figure out first - push and pull second, sometimes you have to apply a little force.