You normally need to use needles and acrow props as shown in the photo.
Once the wall is propped you can knock out below, build up the supporting piers and put in the beam just below the needles. Then build up between the needles, remove the needles later and fill in the holes.
Stonework usually requires more needles than brickwork and is more unstable when doing this kind of work. If you are unfamiliar with construction methods I would get some help in, as although this is a straight forward job for a pro, it can give serious problems to an amateur.
Stone houses like this are common where I live, but the Building Inspectors will usually want an SE to calculate the size of the steel for a large opening.