If the parts, themselves, are not coming off the original backing, I would take the two or three pieces (with old backing) and glue them on to a new backing. Make sure both surfaces are as clean as possible. It'll raise the bindi just slightly, but it'll be more secure than prying everything off and trying to arrange them again. Especially with rhinestones. Usually, once you pry them off, they're kinda dead unless you can get them off without damaging the foil backing.

Sounds like maybe that is what you meant anyway. ;} Good luck!