Detailed instructions on moving item and holdings records can be found at I looked at the Moving Records Information pages on the ITS wiki.
In a nutshell:
If an item needs moving, send Susan an email. This email should include the item barcode, the holdings number to which it is attached, and the number of the destination bib record. (As of 6/2013, Susan is the only person in the TS department who has permission to move item records.) She will do the unlinking at the time of moving.
Only those item records that are not being moved may be deleted if they have no orders and no history attached to them.
To see if an item record has an order attached, look the title up in the search module. "Show" it and click the Overview button in the left-hand pane:
To see if an item record has any history attached to it, get into the Item module and highlight the item record you are interested in. In the left-hand pane choose Functional (vs. Overview) and in the folder titled Item, select History. Open tab 3 Item Changes. If a blank screen appears, it is ok to delete that item record (as long as it doesn't have an order record attached!). If a screen appears documenting even one change in the item record (see below for an example), it needs to be moved to keep that history.