Even though he is not paying rent, he is a tenant. You must folow state law to evict him.
Effective January 1, 2007, the district court is required to provide forms for a Demand for Rent and Eviction Notice (formerly known as the Notice to Quit) in court locations and on the New Hampshire judicial branch website. Although landlords are not required to use these forms, they are still required to use forms with language that complies with both RSA 540:3 and RSA 540:3-1.
Forms: Eviction Notice
&nbs... Demand for Rent
Cost of writ: $1.00
Filing fee: $100.00.
The writ must be purchased from the court, completed (except for the return date), filed with the court, and filing fee paid prior to service of process.
The Demand for Rent (if applicable) and Eviction Notice must have been delivered to the tenant and must have expired prior to the landlord’s filing of the writ.
The court may require an affidavit of ownership/tenancy.
If the writ includes a claim for unpaid rent, a completed statement of the claim and affidavit of damages must accompany the writ to be served upon the tenant. This form will be provided at the time of the purchase of the writ at no extra charge.
It is the responsibility of the landlord to deliver the completed writ and accompanying affidavit of damages and statement of claim (if applicable) to the sheriff for service upon the tenant. With the sheriff's assistance the return date on the writ will be completed. Once service upon the tenant has been made, the landlord must file the return of service with the court.
Upon completion of the court action, should the court grant a Writ of Possession to the landlord, the writ will only be issued upon the filing of a completed military affidavit. This form may be obtained from the clerk’s office.