1) Print "Base.stl".
2) You can make your kissing couple to animate either by hand or by an electric motor. If you want to animate using an electric motor, then purchase the motor "6VDC 45 RPM Pinky Finger Sized Gear Motor 1" Long x 15/32" x 3/8"" from either amazon.com or directly from http://sciplus.com/p/MICROMOTOR_47952 (this is the same motor I used in the "Marbelvator" design), a coaxial power jack (I used Radio Shack part number 274-1583), and a 6vdc power supply with the appropriate connector to fit the coaxial power jack (I used Radio Shack part number 273-316), and print "Gear Motor.stl". Solder wires to motor plus and minus terminals. Slide motor into "Base.stl". Mount coaxial power jack on "Base.stl". Solder motor wires to the coaxial power jack; plus to "center" pin, and minus to "shell" pin. Finally, press "Gear Motor.stl" onto the motor shaft, paying attention to the flat.
3) Print and assemble the remaining parts as per "Assembly.skp".
1) Sand all sides of "Crank.stl". Not too much, just enough such that "Gear Axel.stl" and "Eccentric.stl" slide onto the "Crank.stl" with friction, but not too loose. You don't want "Gear Axel.stl" or "Eccentric.stl" to slide on "Crank.stl" while in operation. If they do slide after assembly, apply a small drop of thick cyanoacrylate once in position.
2) Use a vise, or slip joint pliers (least recommended), to press "Gear Axel.stl" and the 4 "Eccentric.stl" parts on "Crank.stl". Be patient, or you will print more parts.
3) Add a drop of light machine oil inside of the twin guides in "Guide.stl".
4) Roughen the bottoms of "Lift.stl" using 60 to 120 grit sandpaper.
5) Roughen the circumference of each "Eccentric.stl" using 60 to 120 grit sandpaper.
I know it's kind of complicated, so If you have any questions, don't hesitate to comment, and I'll do my best to respond.