Renter breaks lease-how to enforce rent payments

[curiousgeorge]

Relocated last year; unable to sell NYC co-op studio apartment so rented it out. Took 7 months to find a renter – renting a co-op is a lengthy, expensive process because a renter has to be approved and interviewed by the co-op’s management company and the board of directors. Renter is now relocating to another state. Lease expires Dec 31 and has language that binds renter to the rent payments until lease expiry, unless another renter is found and approved – realistically, this will take beyond Dec 31.

How does a lessor enforce the renter, who would be in California, to make payments for the full lease term, that she agreed to in the lease contract?

I am new at this - much appreciate any suggestions/advice. Thanks