Replacing the drum

To replace the dum you need to:

1. Unscrew the hex screw in the rotor (the black rotating disk with hoppers, in the middle of the drum)
2. Lift the disk from the bottom (push it up through the hexagonal holes in the metal base of the drum). Watch the drum-rotor bearing that may fall down while lifting the rotor. 
3. Unscrew the 4 hex screws now visible at the bottom of the drum.
4. Replace the drum with a new one (fit it in the same position as the one you just removed) and screw it back in place with the 4 hex screws.
5. Place the bearing in the center of the new drum's bottom.
6. Fit the rotor back in place (rotate it until fits - it has 2 positions that will work, both are ok) and screw it back with the screw you removed in step 1.
7. Enjoy your Robocoin!