Both STL files are sized for an Ultimaker 2+

pupabot_seperated_part1.stl is large, I will try to print it with 2mm layer height, 15% infill and 65% overhang tree supports. All other settings are default Cura settings. 
pupabot_seperated_part1.stl is smaller, 1mm layer height, 20% infill and 50% overhang tree supports. All other settings default. 

pupabot_assembled.stl is simply for illustrative purposes and should not be printed. 

As I haven't yet printed the model, a demonstration of how it comes apart and is put together is above. When I print it and finalise the model I will also attach photos. 

1. The tail frames and the tail chain are printed separately to make printing more efficient. Slide the frames onto the chain and glue them on. Integrity is not super important for the tail. 
2. Fitting the axel in the tail is a 2-step process: first fit one half of the axel through the end vertebrae, screw the other half of the axel on. Then line up the fitted axel and end vert with the inside of the holes in the chassis. Slide the axel caps into the chassis holes from the outside, into the axel. The larger axel half fits the cylindrical cap and the smaller axel half fits the prism cap. 
3. Fit a suede cone over the tail and attach the fabric to the frames by threading a needle through the holes along the perimeter of the tail
4. Tie the ends of the suede cone to the loops on the inside of the shell. 
5. Insert LEDs and wire into the eye holes in the back of the head piece. 
6. The acrylic plates supporting the battery and the microbit (and all of the connections) should be inserted before connecting the head.
7. The head needs a bit of a squeeze to take out/put in. The flatter surface is 'Up' so it is printed upside down. 
8. The legs are held together by servos. The second joint should be assembled first, fitting the claw behind the servo body screws. The servo should be facing the inside of the body. Fit the forearm piece over the servo head with the side that has a gap for the shorter servo arm. Fit servo arm over it and screw it on. Once again it should be facing the centre-line of the body. 
9. Fit the second servo into the other side of the forearm piece. The screws should be facing upwards. The arm piece should be fitted behind the servo. Then fit the second servo head through the hole in the shell, screwing a double servo arm on the other side once again. 
10. Repeat on other side.