Once the control panel is removed from the side of the machine, carefully turn it around so that the button-side faces the machine and the circuit board is exposed towards you.
Remove the four Phillips head screws as indicated here. Place the face off to the side when removed.
Turn the circuit board around and remove the two cables. These are two different sizes and are both polarized with tabs that only allow them to be reinserted in the correct orientation.
The control chip can be prized out of its socket using a small screwdriver or other suitable tool. One end of the chip is somewhat blocked by two disk capacitors- pry from the other end. Work slowly.
Before inserting the new chip make sure that the pins are aligned and straight. They are easily bent back into shape if necessary, but do so with care.
When replacing the chip take note of the proper orientation. There is a notch in one end of the socket on the circuit board and another in one end of the control chip. These need to be aligned. Place the chip in place making sure all the pins are correctly placed in the socket. Place the board flat on a towel or other similar surface and evenly press the chip into place taking care not to bend the pins.
Replace the two cables, matching the orientation and routing as shown above when the panel was removed. Align the face on he control panel making sure that the switch buttons are aligned with the panel's push areas and the four screw holes are aligned. Loosely replace all four screws and then tighten them. Do not over tighten the screws!