Ring resizing?

I have a ring that I made in a size 7.25 for sale; a buyer who is a
size 9 wants it.

The most I have ever stretched a ring is up to 1 full size, with a
roller stretcher. The stone, which is already set, is very unique, so
this would be my preferred option, but I am afraid that stretching it
almost 2 sizes might be too much for the sterling silver.

Does anyone have any advice on stretching?

Am I going to have to pop the stone out and sleeve some more silver
into the band?

thanks,
-stacy