Ok, there is no legal requirement for a tenant to sign a 10 day notice. The applicable statute is N.C. Gen. Stat. § 42-3 which states:
""§ 42-3. Term forfeited for nonpayment of rent.
In all verbal or written leases of real property
of any kind in which is fixed a definite time for the payment of the rent reserved therein, there shall be implied a forfeiture of the term upon failure to pay the rent within 10 days after a demand is made by the lessor or his agent on said lessee for all past-due rent, and the lessor may forthwith enter and dispossess the tenant without having declared such forfeiture or reserved the right of reentry in the lease.""
Once you deliver or post the 10 day Demand for Rent, if the tenant doesn't pay the entire amount within that period, you have to file for summary ejectment in District Court. The sheriff will then serve a summons on the tenant and they have 7 days to respond to the summary ejectment complaint. If they don't respond, the landlord would appear on the court date and get a default judgment. Then tenant has 10 days to appeal. If they don't appeal, landlord can then get a "Writ of Possession" from the court clerk. Within 3 days the Sheriff will notify the tenant of the Writ of Possession. Within 5 days the Sheriff will padlock the property. The tenant will then have 7 days to remove all personal property, or else the landlord may dispose of it.
So from the time you deliver the 10 day Demand for Rent, it will take around 40-45 days, depending on the court and sheriff.