Renewing tenant lease with new roomate

[Kay M.]

Hello. I was hoping to get advice. I currently rent a sfh to 3 roommates. They all share and pay rent as one tenant and have 2 pets. Turns out that when the lease is up they want to renew with a new roommate. One previous roommate is leaving and taking one pet with them. Originally I would credit and background check the new person and let them deal w the deposit exchange among themselves. What would you do in this case? Refund partial pet dep. Credit check background new person. Then sign lease renewal for 3?