Remove the strings from the fiddle by loosening the pegs at the neck and removing the fine-tuning screws near the bridge of the fiddle.
Examine the fiddle to see if there are any screws holding the top and the bottom of the fiddle together. If there are, you will need to remove the screws by unscrewing them.
Saw the heel of the neck off leaving some of the heel intact to prevent sawing through the back of the fiddle.
Remove the neck from the fiddle by separating it from the back.
Set a 10-millimeter strip of wood against the top of the fiddle neck using a small amount of wood glue. Use a clamp to hold the pieces together for two hours.