Convert WowWee TriBot toy robot from Remote IR control, to arduino control.
Purchase WowWee Tribot 
WowWee Tribots retail at around $300, Amazon discounts a bit and they sell used from $40 on up.
The robot is officially called the "WowWee Tribot Talking Companion." There is a Wowwee Mini Tri-bot that retails for around $21 that should not be confused with the bigger brother. Online it is hard to tell them apart. The Mini Tri-bot does not ship with universal or Omni wheels, has just one motor and in general is not worth an arduino.
Take off the Arms 
The arms are held on by three screws around the arm socket and one screw at the waist. Remove them. The black handle is held on with two screws. Do not remove them. The goal is to keep the arm assembly together as much as possible. There are two screws near the black handle, towards the back near the back IR transmitter and receiver. Remove one of these screws. The split apart the arms. The black handle should hold the shoulders together. There is a white bar that holds the back shoulders together. Replace the last screw removed.
The breast plate is a speaker. There are 3 infared transmitters and 3 receivers. They are used for the "Home" function where the robot follows someone with the remote and are used to avoid collisions. This tutorial does not show how to restore this functionality with the arduino.
Remove Existing Controller 
Remove torso IR Cables 
Remove the white wires that go to the head switch on the torso. Don't remove the switch. Remove the white wires from the switch that plug into the existing controller.
Remove the ribbon cable coming up from the motor controller and the power cable coming up from the motor controller through the torso.
Remove head Cables 
There are two ribbon cables and one power cable to the head that need to be removed.
Remove Existing Logic Board 
Four screws hold on the existing logic board. The arduino almost fits 2 of the screws. One screw has to be forced in at an angle, but both the Uno and Duemilanove both mount at two points. The arduino is larger than the original logic board. Putting the arms back on over the new arduino like they went over the old logic board is not an option.
Remove upper torso and Head 
Reroute cables from Head 
Remove Hip Support 
Modify Motor Controller 
Cut Ribbon Cable and Head Power Cable 
Remove IC Solder Pads 
Solder Ribbon Cable to IC Pad 
Slice into Battery Power 
Add Encoder Power from Arduino