All holes are predrilled and installation is simple bolt-on procedure. Installation details and needed hardware can be seen HERE, in Section III.
Although the rack is very sturdy and strong, we recommend using the top case only on the road (not off-road) and limiting the weight carried in the top case to 5 kg.
Also, this rack is designed to carry a top case a bit closer to the rider than if "dedicated" top case carrier is used. Main purpose of our racks is to support and carry soft luggage, so they are low profile and compact with the bike. Top case compatibility is just an added benefit. The top plate of the rack sits just behind the seat and not far in the back - it doesn't protrude the vertical line of the rear mudguard. A top case is placed just above the rear end of the seat, as shown in the photos. This position is great for weight centralization, but it doesn't leave much room for a pillion. Pillion comfort depends on the pillion size. For short rides, it will be OK. But if you plan two-up touring with a grown-up passenger and a top case, better consider some top case carrier that carries the top case more towards the rear.
And it is worth noting that top case can't be installed if some of the higher (thicker) aftermarket seats are used, as front of the top case sits just above the stock seat. Works great with standard stock seat and Rally version seat.
If you prefer small top cases, this 38 ltr. top case is as small as it gets.