You need to remove the front panel first and then remove the top, when I first tried I was scared I was going to break it, but it has 8 plastic pins which hold it in place that will slip out. To remove the front I pulled it outwards from the bottom to about a 45 degree angle then pulled the top out. Then to remove the top, from one end I pushed it upwards and kept pushing until it release. You can also join the NZXT discord server if you require any more help.