Within your list in BOM Insight, from the Projects dropdown you can transfer ownership of your BOM. To transfer the editing rights, from the dropdown click on Change Ownership.
This will open the Transfer Ownership modal. You can enter the email address of a licensed team member in order to transfer the editing ownership of your list to them. You can add a comment as needed, and then click on Transfer Ownership to give your BOM's editing rights to your colleague.
This will give your colleague editing control of the list and you will now have read-only access. They can transfer BOM ownership back to you if you're needing to make additional changes later.