There is a place in Main, USA, that is reported to do this, one-off.
But I was considering doing it myself. The hot-plate or electric griddle
technique ($30 at Walmart). Googling around shows many successes. But with a
BGA I've yet to see it.
You would have better success with a more focused heat source that a
griddle plate.
Particularly if there are other SMD parts surrounding it, and there no
doubt is.
You bring the whole assembly up to about 160 F. Then, you apply some
heat to the bottom, directly under the chip, to bring that part of the
board up a couple hundred more degrees, then you place the focused heat
on top over the chip, all the while preparing to grab it with good
tweezers or a four corner mechanism that you build specifically for
removing the chip.
You cannot pull the chip before all the balls reflow, and you cannot
"pull" at all really. If the temps are right, it will reflow, and you
should be able to lift it off with NO force required, and you should
never apply any either.
I would still get someone with a rework station to replace it though.
The surface has to be prepped after the old chip comes off, and other
things that require someone with experience to perform to keep from
buggering up the board.
You may succeed, but the odds are below 50%, and decrease another 10%
with each additional 25 balls.
Even when done in a pro lab, it is difficult, and x-rays are required
after.