Water bottle can be problematic.
Filling the food container was a breeze, you can either take the food container off or fill it in place. if you remove the food container to fill it, don't forget to close the cover over the chute opening so the food does not drop out, once you have the food container back in place you can open the chute cover so as much or as little as needed to feed your cat. When selecting a water bottle, try using 500ml or 1lt bottles as these seem to be more rigid than the 2lt bottles, also before trying to attach the bottles make sure you remove all remaining parts of the cap as this can prevent the bottle from screwing into the water dish/tray.
All in all, i love this feeder but I do wish I'd used a smaller bottle first...