Looking at the specifications and the parts listing for the oven and the many voltages that they manufactured them in, they are not normally convertible.
In order to attempt to change one over, you would have to got through the oven and change many, many parts over and do some rewiring to add to the situation.
None of the major components are dual voltage, so heating elements, motors, transformers, contactors, timers etc, would have ot be purchased and rewired to make them over for the new voltage.
I would think it is a very expensive attempt and still may be a single part or many that may not be available and after doing that purchasing, you may not be able to complete.
Is that what you wish to do?
A simple transformer would cost 5 times less most likely and be an easy installation and the preferred way to go.