At this time you cannot delete a lock from your account. You can, however, mostly hide it. A good way to more or less hide a lock is to:
1. Create a holding facility.
2. Transfer any locks you don't have, or are damaged to this facility.
3. Modify your users' facilities so they do not have access to the holding facility (optional).
4. The locks will still show up in the initial list of locks, but they will not show up in any list for a specific facility.