Importing Leads

I tried to import leads from my database. I don't have first name or last name in some of the records that are being imported. How do you remove the mandatory field requirement so I'm not losing 1/2 of my database. The field should be blank as my admins job is to get correct information as she is making calls to the businesses. How do I remove this mandatory field requirement? Thanks, Beau Carlisle Enterglobal, LLC