We have a built in kitchen unit which houses a single oven with a microwave
above.
The microwave sits on a shelf which is part of the carcass of the unit.

I want to fit a double oven. There is plenty space but I will need to remove
the shelf the microwave sits on.
The outside face of the kitchen unit does not have an signs of fixings for
the microwave shelf. I presume the shelf is pegged and glued in position.
How can I remove this shelf without causing any damage to the built in unit,
secondly will removing the shelf affect the strength or stability of the
unit or will I have any problems fitting a double oven in?

Thanks.

Ian