First you will need to turn off or disconnect the power source to your oven, then remove the oven console or control panel for access to the control board.
When replacing a bad oven circuit board with a new board, it is a good practice to have the new replacement board out of its packaging or box and to hold it in front of the old board so that you can examine both of the oven circuit boards and make certain that they are the same before pulling any wires loose from the existing board and replacing.
If you are not familiar with all of the wires that are connected and will need to be disconnected and transferred from one board to the other, have your phone handy and snap a few good photos of the bad circuit board while it is still connected in your oven for future reference, if needed.
Now that you are sure that both of the boards are the same you can transfer the wires from the old board to the new circuit board.
Once you have transferred all of the wires from the old control board to the new replacement circuit board you will need to replace the oven console or control panel, turn the power source back on. You will then need to program the new oven circuit board, following the instructions for your oven model.
The circuit board has a life span just like any other household appliance parts do and can wear out from use and age. Lightning storms/strikes cause a lot of havoc on appliances and are responsible for damage to many circuit boards. Electrical power surges and flood waters or just moisture/condensation can also be to blame for a faulty oven circuit board.