Unfortunately, no.  This is incompatible with the way the underlying non-member database architecture works.  In a nutshell, the non-member data table (MSNONMBR) is set up so that the SSN/TIN is the key piece of identifying data that separates one non-member record from another (it’s actually often referred to as “the key to the file”).  The SSN/TIN is also what links a non-member to other memberships, via things such as secondary names (for joint owner and beneficiary relationships), IRA beneficiaries, loan co-signers, etc.  Our database structure means that a key field cannot simply be altered; that record must be deleted and a new one created with a different key.  That’s different from how the memberships table (MASTER) works, because there the account base can be the key, which allows the SSN/TIN to be changed.