Tenant wants "Lease Buy-Out". How to respond?

[Manoj N.]

Current lease by three tenants (joint and several)  ends May '17. One tenant wants to leave sooner and he offered me a deal he calls "lease buy-out". Instead of him finding a suitable replacement (which I had agreed) he offered to pay 3 months of rent (his part) if I take the responsibility to find a replacement. On one hand, I want to help him out and the extra payments will cover possible delays in finding a replacement. However, there is this hassle of finding  a tenant that pass my checks and also is acceptable to other two. Any thoughts ?