People increasingly live their lives online, accruing large collections of digital possessions, which symbolically represent important relationships, events, and activities. Most HCI research on bereavement focuses on retaining these significant digital possessions to honor the departed. However recent work suggests that significant digital possessions may complicate moving on; they function as both comforting and painful reminders but currently provide inflexible methods for disposal. Little work has investigated the disposal of digital objects as a means of letting go. To better understand this we interviewed 10 psychotherapists who employ rituals of letting go to help patients overcome loss in situations such as a divorce, a breakup, or a stillbirth. Patients disposed of either natural artefacts or symbolic personal possessions through actions such as burning, burying, or placing in a body of water. Therapists noted people increasingly have digital possessions, and that the act of deletion does not offer the same cathartic sense of release as disposal of material artefacts. Based on analysis of this grief therapy, we propose a new conceptual framework for rituals of letting go that highlights temporality, visibility, and force. It provides a vocabulary to talk about disposal. We then offer design implications connecting the rituals of letting go to the disposal of digital things. Based on our interviews and analytic framework, we propose novel technologies that better connect the embodied nature of letting go rituals to the process of digital disposal.