To archive an element in Simple CRM :
1) Go to the file of the element concerned (contact, company, project)
2) Click "Edit".
3) The editing window of the element is displayed.
4) Click on "Archive", then click on "Validate" on the confirmation message.
5) The item appears in the "Archived" list (at the bottom of the Contact, Company, Project modules).
If you want to DEFINITIVELY delete the archived items:
1) Go to the Admin module (top menu -> Admin)
2) Click on the "Delete archives" tab
3) Follow the instructions.