Miscellaneous Key Operator / User Codes

I've just had a R160 returned to the office after upgrade and can't contact the school until the new year to find what user codes they set.

Basically, as this machine is for export is there an SP code I can use to fully remove the Key Operator code and/or User Codes.

Would a full HDD format do this? (doubtful)

Memory Clear? (I don't want to do a full clear if possible)

Thanks in advance