Tenant's broke up and the boyfriend moved out

[Brian Zaug]

Hey all, I had a couple with 3 kids move into one of my apartments a few months ago.  We gave them a 7 month lease so it renewed on Aug 1st with the rest of my leases and if all was well, I'd renew them with a 1 year lease.  

So I got a call from them this morning saying they broke up and the guy is moving out today.  He took all his stuff and left.  The girlfriend has enough income to cover the apartment and wants to stay.  The boyfriend is asking for me to remove him from the lease.  My question is do I have to give him any of the security back or can I simply remove him from the lease and have the girlfriend sign a new lease with her just on it?  Is he entitled to half of the security?  He's breaking the lease by moving out...not sure here..Thanks for your input..