without knowing the exact spell, i don't know if there's a particular reversal spell one needs to cast.
if your whole family believes they've been cursed it'll be easier than you trying to convince them or get them to do things. start by having a purifying bath with sea salt. sit in the tub, and pour the water all over, as you do, visualize the water as a glowing light, and your skin as grey/black. as the water touches you, you begin to glow with with the light, and the water starts to turn a grey. then make a protection charm for yourself and each family member effect [note, the family should also do the bath.] third thing you should do is cleanse your house. move all the furniture and clean every inch with a cleansing brew. the doors and windows should all be open and you should clean from the middle of the room out. when you leave each room, shut the door leading to it. fourth [and possibly final] step, take sage smudge and waft the smoke into every inch of your house, closing windows and doors leading outside as you go. say a chant asking for protection from negative energies.
kind of a long process, but that's probably what you should do. if your family doesn't believe in magic, or you've been cursed, it might be a bit harder to move everything, get them to wear charms and whatnot, but you could always change it a bit. say you want to do some spring cleaning. instead of sage, sit and meditate, try to fill the house with positive energy, and create a shield around your house the same way you would place a shield around yourself.