Girl moved out but Guy does not want to take her name off lease

[Ekrem Bermek]

Hi Bigger Pockets,

My tenants are a couple that just split up. The girl has moved out and wants her name off the lease. She is OK not getting back any security deposit. The guy does not want to take her name off the lease. I'm OK removing her from the lease. Do I need his permission to remove her from the lease? What mechanism do I use to remove her from the lease? The guy will not sign a lease amendment stating he is just the tenant. Do I need a lease amendment signed by all parties?

Thank you!