unfreeze.py

def unfreezeTransformations(selection):
    originalCenter = cmds.getAttr('%s.center' % selection)[0]
    cmds.move(originalCenter[0] * -1, originalCenter[1] * -1, originalCenter[2] * -1, selection, absolute=True)
    cmds.makeIdentity(selection, apply=True, translate=1, rotate=1, scale=1, normal=0)
    cmds.move(originalCenter[0], originalCenter[1], originalCenter[2], selection, absolute=True)