To gain access to the inside of X2000FN thumbscrews need to be removed from either side panel and then the panel simply pulls off. Below shows a picture of the mechanism which Lian Li have used to affix the panels to the chassis metal plugs fit into a clamp to provide a snug fit. Relative force is required to remove each panel since there are a series of plugs to detach.
Side panels use a plug/clamp mechanism
Casting our eyes onto the inside of the case we see the interior is split into three different zones. The bottom is designated for the PSU and HDD storage, the middle is for motherboard and HDD storage and the upper is for HDD storage and optical drives. HDD storage in the lower and upper regions have the added bonus of being hot-swappable with docking ports. Separating components into different areas results in better thermal control and helps to assist with better cable management.
X2000FNs expanse means an assortment of different form factors can be accommodated. Inside, M-ATX, ATX, XL-ATX and E-ATX are all supported (although Lian Li do not state XL-ATX is compatible on their website).
A look at the internal layout with three zones
Behind the motherboard tray