The undersigned hereby covenants and agrees that if there shall occur any default by Tenant in the payment of fixed rent or additional rent or any other charges set forth in the Lease, or if Tenant shall default in the performance of any of the covenants, terms, conditions and agreements contained in the Lease then the undersigned shall in each and every instance up to and including the Release Date (as defined below) (i) pay such fixed rent, additional rent and any other charges due and payable by Tenant to Landlord (ii) faithfully perform and fulfill all of such covenants, terms, conditions and agreements to be performed by Tenant as set forth in the Lease, and (iii) pay to Landlord all consequential damages that may be incurred by Landlord as the result of any default by Tenant under the Lease including without limitation all attorneys’ fees and disbursements incurred by Landlord as a result of any such default and/or the enforcement of any of the provisions of the Good Guy Clause. The “Release Date” shall mean the upon which Tenant returns to the Landlord the keys to the Premises and surrenders possession of the Premises in the condition required by the Lease as of the expiration or termination thereof free of all tenancies or rights or claims of occupancy by Tenant or any party claiming through Tenant.

Now in English Please

The bolded phrases above are the two most integral parts of the "good guy clause" . The release date, is the when the tenant returns the keys and hands the property back to the landlord. Essentially as long as the tenant follows the rules and doesn't tear the place up, or sublet it to vagrants, then they are basically released of their duty to pay rent once they return the keys and move their stuff out. The tenant is still responsible for the rent up to the point where they hand back the keys.