Yes you do need to contact the customers. If you download guidance note 10 from here https://www.fsai.ie/...blications.html it gives you a mock recall procedure which you can tailor to suit your needs. It also gives you a template for a report. Main thing is to keep copies of all correspondence , and keep a timeline of each step as you go through the procedure. f ex.
Complaint received by QM @ 11:15
Recall team convened at 11.30
Decision tree used to determine if a recall is required: 11:35
Production manager tasked with gathering traceability documents 11:40
Competent authorities alerted @ 11:45 etc etc
Start with Guidance note 10, it has been invaluable to me....