It can take three to six months for a nipple piercing to heal completely, according to the Center for Young Women's Health. During the healing process, the wearer should not change the stud provided at the piercing. After the piercing heals completely, the wearer can remove the stud and replace it with new jewellery.
Wait Until it "Skins Over"
The piercing experts at Tribalectic Magazine, "the definitive source for everything pierced," report it is sometimes OK to remove and replace the original jewellery after the piercing completes its initial healing process, or "skins over." After the wound skins over, and you experience no physical pain or discomfort when you agitate the piercing, they suggest it may be OK to remove the original jewellery and replace it with a new piece.
The piercing experts at both Young Women's Health and at Tribalectic Magazine agree that the safest choice is to wait the allotted three to six months until the piercing heals completely. By this time, the piercing should have skinned over and be free of any pain, discomfort, redness, swelling or infection. It is then safe to remove the original stud and replace it with new jewellery.